Technical Engine first start but..

[sprie]

I spent a couple of hours trying to get the engine to start today after the rebuild with the rebuilt head. I was pretty sure the main issue was timing.

I am confident I have the camshaft/crankshaft synchronised: if I move the camshaft 1 gear tooth either way on the cambelt, I can feel the pistons/valves meet when I hand crank.

I loosened the fuel pipe to cylinder number 1 and hand cranked – and I could see when a medium size drop of fuel appeared. It was consistent, so my plan was to get the timing such that this happened just at the end of the compression cycle.

As this bears no relationship to the marks on the fuel pump gear, it was a best-guess-exercise, trying one likely looking position, then tweaking by 1 gear etc.

Anyway, in the end, the engine started (!) which is always an exciting moment.

I had two issues:

1. As I have not connected up any of the coolant system (i.e. no coolant), I wanted the engine to stop before it got warm. When I removed the key, it carried on running. In a bit of a panic, I loosened the drain plug under the fuel filter. The engine did stop, but I don’t believe my action was the cause.
2. The engine was loud and clattery.

I have not tried running it again, as I first want to understand what is going on.

Issue 1: I presume that when you turn the ignition key off, the engine should stop promptly? Is that correct? If so, I presume there is a solenoid that cuts the fuel (I have connected two sets of leads to the fuel pump, one on the side, one on the front)? Is there a reason why the engine might not stop immediately?

Issue 2: What are the likely causes of the clatter? Is this to be expected of a diesel engine of this age, or is this a sign of an issue e.g. timing. Does it need to be advanced or retarded?

any ideas appreciated

 

[Communicator]

I spent a couple of hours trying to get the engine to start today after the rebuild with the rebuilt head. I was pretty sure the main issue was timing.

I am confident I have the camshaft/crankshaft synchronised: if I move the camshaft 1 gear tooth either way on the cambelt, I can feel the pistons/valves meet when I hand crank.

I loosened the fuel pipe to cylinder number 1 and hand cranked – and I could see when a medium size drop of fuel appeared. It was consistent, so my plan was to get the timing such that this happened just at the end of the compression cycle.

As this bears no relationship to the marks on the fuel pump gear, it was a best-guess-exercise, trying one likely looking position, then tweaking by 1 gear etc.

Anyway, in the end, the engine started (!) which is always an exciting moment.

I had two issues:

1. As I have not connected up any of the coolant system (i.e. no coolant), I wanted the engine to stop before it got warm. When I removed the key, it carried on running. In a bit of a panic, I loosened the drain plug under the fuel filter. The engine did stop, but I don’t believe my action was the cause.
2. The engine was loud and clattery.

I have not tried running it again, as I first want to understand what is going on.

Issue 1: I presume that when you turn the ignition key off, the engine should stop promptly? Is that correct? If so, I presume there is a solenoid that cuts the fuel (I have connected two sets of leads to the fuel pump, one on the side, one on the front)? Is there a reason why the engine might not stop immediately?

Issue 2: What are the likely causes of the clatter? Is this to be expected of a diesel engine of this age, or is this a sign of an issue e.g. timing. Does it need to be advanced or retarded?

any ideas appreciated

Issue 1 The fuel cut off valve in the pressure head of the pump is held open by the "stop" solenoid. I use the inverted commas as really "stop solenoid" is a misnomer, as it is effectively a go solenoid. If the valve sticks open, the engine will continue to run.
Issue 2 Unfortunately, by running the engine without any coolant for more than a few seconds, you may have scuffed a piston.

I think that @bugsymike have something to add.

 

[bugsymike]

Issue 1 The fuel cut off valve in the pressure head of the pump is held open by the "stop" solenoid. I use the inverted commas as really "stop solenoid" is a misnomer, as it is effectively a go solenoid. If the valve sticks open, the engine will continue to run.
Issue 2 Unfortunately, by running the engine without any coolant for more than a few seconds, you may have scuffed a piston.

I think that @bugsymike have something to add.

Certainly not ideal, personally I have confidence in my work and always fill coolant, oils, etc. No disrespect if still on the learning curve, we all were at some time.
I have seen mechanics running engines with no water after rebuild as nervous about their work and got away with it, personally I would not have employed them.
Anyway if genuinely only for a very short time then fingers crossed no further damage.

Firstly are you 100% the valve timing is correct?
Second moving the injection point by 1 tooth on gear will be quite a large amount. if injection timing too far advanced it will give a hard diesel knock, so needs correcting if that is the cause of knock.
If you are sure about valve timing then find TDC on No.1, put a clear mark on crank pulley at 5 degrees before TDC unless you have the exact point in degrees, as a starting point (I did this using a child's protractor and set a York Diesel engine at 12 Degrees that I fitted in a Land Rover), then turn the engine the correct direction towards TDC firing on No.1 and using the "Swan neck" method with injector No.1 pipe off to see precisely when it injects and then check how near or far from that 5 degree mark on crank pulley is. This is not exact, but should give a guide to where your injection is.
By the way it can be quite accurate when using the correct swan neck tool which is a glass tube and when full of diesel but with an air bubble trapped in the swan neck, as the pump is very slowly turned the bubble will jerk at the exact point as injector pump opens for that cylinder.
In an ideal World you would have marked pulleys when dismantling, but if this rough and ready method gives you a guide to work from it is a start. Fine adjustment is usually by small movement on the injection pump in it's slots or where possible by freewheeling pulleys etc.
Incidentally when faced with a engine racing away slackening all the injector pipes would be quicker than waiting for a fuel filter to empty.
My other main concern is if engine "ran away" due to oil in the inlet manifold or some such causing engine to run uncontrollably leading to destruction!!! I have seen this and my quick action in stalling the vehicle in gear prevented damage, so best avoided as many have blown up totally.
However in your case it sounds like a wiring issue giving permanent feed to fuel solenoid, it is important to fix this before going any further.
Hopefully the noise is just the injection too far advanced, did it run on all four cylinders smoothly?
By the way when rebuilding engines I am always generous with the oil can, both around the pistons and bores, bearings etc. if full overhaul and also around the valve gear as initial start up before oil pressure builds is a worrying time.
There are cheap diesel timing lights or adapters to fit petrol timing lights available, I have a Bosch one that uses the impulse from the fuel at injection point to trigger the timing light strobe. Mine was expensive and shows Rpm and advance in degrees also.

 

[sprie]

Certainly not ideal, personally I have confidence in my work and always fill coolant, oils, etc. No disrespect if still on the learning curve, we all were at some time.
I have seen mechanics running engines with no water after rebuild as nervous about their work and got away with it, personally I would not have employed them.
Anyway if genuinely only for a very short time then fingers crossed no further damage.

Firstly are you 100% the valve timing is correct?
Second moving the injection point by 1 tooth on gear will be quite a large amount. if injection timing too far advanced it will give a hard diesel knock, so needs correcting if that is the cause of knock.
If you are sure about valve timing then find TDC on No.1, put a clear mark on crank pulley at 5 degrees before TDC unless you have the exact point in degrees, as a starting point (I did this using a child's protractor and set a York Diesel engine at 12 Degrees that I fitted in a Land Rover), then turn the engine the correct direction towards TDC firing on No.1 and using the "Swan neck" method with injector No.1 pipe off to see precisely when it injects and then check how near or far from that 5 degree mark on crank pulley is. This is not exact, but should give a guide to where your injection is.
By the way it can be quite accurate when using the correct swan neck tool which is a glass tube and when full of diesel but with an air bubble trapped in the swan neck, as the pump is very slowly turned the bubble will jerk at the exact point as injector pump opens for that cylinder.
In an ideal World you would have marked pulleys when dismantling, but if this rough and ready method gives you a guide to work from it is a start. Fine adjustment is usually by small movement on the injection pump in it's slots or where possible by freewheeling pulleys etc.
Incidentally when faced with a engine racing away slackening all the injector pipes would be quicker than waiting for a fuel filter to empty.
My other main concern is if engine "ran away" due to oil in the inlet manifold or some such causing engine to run uncontrollably leading to destruction!!! I have seen this and my quick action in stalling the vehicle in gear prevented damage, so best avoided as many have blown up totally.
However in your case it sounds like a wiring issue giving permanent feed to fuel solenoid, it is important to fix this before going any further.
Hopefully the noise is just the injection too far advanced, did it run on all four cylinders smoothly?
By the way when rebuilding engines I am always generous with the oil can, both around the pistons and bores, bearings etc. if full overhaul and also around the valve gear as initial start up before oil pressure builds is a worrying time.
There are cheap diesel timing lights or adapters to fit petrol timing lights available, I have a Bosch one that uses the impulse from the fuel at injection point to trigger the timing light strobe. Mine was expensive and shows Rpm and advance in degrees also.

Hi

Thanks again and to Communicator for your help. Its a bit like Air Traffic Control talking to a novice in a plane when the pilot has fainted to get them to land! I have only rebuilt one engine before and this is my first diesel and I don't have a Haynes etc.

Before changing anything, i went this morning to try and see the position of the drop of fuel. I saw it first time, but then I started doing the turns v slowly to get some accuracy but there was no drop. I wonder whether i need to have ignition on to open the fuel feed - and i am not widely happy about turning the engine with ignition on in case it starts.
I can understand how the Swan Neck tool would be a lovely way to see exactly when tool is delivered.

As mentioned in previous posts, my working hypothesis is that the garage that worked on this engine previously who "got it to run for 5 minutes but then it stopped and wouldn't run again" didn't see the water in the fuel tank/feed and that some water may have been sitting in the fuel pump. This might explain the stickly valve. I am hoping that a flow of fresh diesel may help free it up.
The engine only ran a total of 15 - 20 seconds, and my releasing the fuel filter plug could not be the cause for it stopping. I like the idea of releasing the connectors to the injectors - i will have the appropriate spanner on hand next run.

I have double checked the valve positions, I think even 1 tooth either way would lead to piston/valve clash.

Regardless, as well as no coolant, i haven't put any of the covers on over the cambelt. I had a look at these, and i notice that the metal backing cover has a small hole about 2 o'clock, which must be for the timing. Having now got the timing to the point that the engine has run, I can now see:
1) holding the cover in place by hand, adding a mark on the gear through this hole, i can see it is diametrically opposite a "real" mark on the gear
2) there is a "real" mark on the fuel gear at 6 o'clock.

I have been assuming that Cylinder 1 is the one next to the cambelt and this is the one i should use to set my timing.
But now i am thinking that if I use the cylinder next to the gearbox for timing, this would lead to
1) the camshaft "real" mark showing through the hole and
2) the fuel gear mark being at 12 o'clock (i.e. "tdc").
I did read that the Citroen/Peugeot treat cylinder next to gearbox as cylinder 1 but google AI (!!) told me that my Fiat was the opposite.

If i took this new approach would mean that I could use "real" marks on all three gears, and have more precise ability to check their positions i.e.
1) crankshaft has its TDC mark
2) camshaft would be mark through the hole
3) fuel pump would be 12 o'clock (AND having just looked again at the cover, i can see a triangular imprint at this position which i think is marking this position).

So
1) I need to remove the camshaft gear in order to install the metal cover (which is annoying)
2) I see that the fuel pump is currently attached in a position which would allow me to turn it a tiny bit to advance it, but no retard. I will reposition the fuel pump in a middle position, which would allow a bit of movement in either direction. At least that way, i might be able to work out which direction is "better" and which is "worse".

And I presume i use the cylinder near the gearbox for timing?

 

[Communicator]

Hi

Thanks again and to Communicator for your help. Its a bit like Air Traffic Control talking to a novice in a plane when the pilot has fainted to get them to land! I have only rebuilt one engine before and this is my first diesel and I don't have a Haynes etc.

Before changing anything, i went this morning to try and see the position of the drop of fuel. I saw it first time, but then I started doing the turns v slowly to get some accuracy but there was no drop. I wonder whether i need to have ignition on to open the fuel feed - and i am not widely happy about turning the engine with ignition on in case it starts.
I can understand how the Swan Neck tool would be a lovely way to see exactly when tool is delivered.

As mentioned in previous posts, my working hypothesis is that the garage that worked on this engine previously who "got it to run for 5 minutes but then it stopped and wouldn't run again" didn't see the water in the fuel tank/feed and that some water may have been sitting in the fuel pump. This might explain the stickly valve. I am hoping that a flow of fresh diesel may help free it up.
The engine only ran a total of 15 - 20 seconds, and my releasing the fuel filter plug could not be the cause for it stopping. I like the idea of releasing the connectors to the injectors - i will have the appropriate spanner on hand next run.

I have double checked the valve positions, I think even 1 tooth either way would lead to piston/valve clash.

Regardless, as well as no coolant, i haven't put any of the covers on over the cambelt. I had a look at these, and i notice that the metal backing cover has a small hole about 2 o'clock, which must be for the timing. Having now got the timing to the point that the engine has run, I can now see:
1) holding the cover in place by hand, adding a mark on the gear through this hole, i can see it is diametrically opposite a "real" mark on the gear
2) there is a "real" mark on the fuel gear at 6 o'clock.

I have been assuming that Cylinder 1 is the one next to the cambelt and this is the one i should use to set my timing.
But now i am thinking that if I use the cylinder next to the gearbox for timing, this would lead to
1) the camshaft "real" mark showing through the hole and
2) the fuel gear mark being at 12 o'clock (i.e. "tdc").
I did read that the Citroen/Peugeot treat cylinder next to gearbox as cylinder 1 but google AI (!!) told me that my Fiat was the opposite.

If i took this new approach would mean that I could use "real" marks on all three gears, and have more precise ability to check their positions i.e.
1) crankshaft has its TDC mark
2) camshaft would be mark through the hole
3) fuel pump would be 12 o'clock (AND having just looked again at the cover, i can see a triangular imprint at this position which i think is marking this position).

So
1) I need to remove the camshaft gear in order to install the metal cover (which is annoying)
2) I see that the fuel pump is currently attached in a position which would allow me to turn it a tiny bit to advance it, but no retard. I will reposition the fuel pump in a middle position, which would allow a bit of movement in either direction. At least that way, i might be able to work out which direction is "better" and which is "worse".

And I presume i use the cylinder near the gearbox for timing?

No! I that is cylinder No. 4. I would expect to use No. 1.

Transverse front wheel drive vehicles only became popular with the introduction of the "Mini" in the late 1950's. Previously engine and gearbox were longditudinal, with engine at the front. So No. 1 cylinder was the one at the front. With transverse engines we still count from the non drive end.
However I had a Saab 99 for many years which had No. 1 at the rear with clutch behind the radiator. There was a chain drive down to the gearbox underneath the engine.

 

[bugsymike]

No! I that is cylinder No. 4. I would expect to use No. 1.

Transverse front wheel drive vehicles only became popular with the introduction of the "Mini" in the late 1950's. Previously engine and gearbox were longditudinal, with engine at the front. So No. 1 cylinder was the one at the front. With transverse engines we still count from the non drive end.
However I had a Saab 99 for many years which had No. 1 at the rear with clutch behind the radiator. There was a chain drive down to the gearbox underneath the engine.

Engine ignition will need to be on to open the solenoid valve to allow fuel to the injector pump. If you are worried about turning the engine whilst checking timing with ignition on, then slacken all four injector feeds, it only needs to be a little. The No.1 will still have it's fuel injection via the injection pump at that point and you can feel safe that the engine will not start. It's like pulling plug leads off a petrol engine, take one or two off and engine may keep running, but not with all off.
Note for any one else reading this, it is all for pre Common Rail diesel systems.!
You may be able to make a simple "Swan neck" tool using clear plastic tubing pushed onto the No.1 injector feed to check timing. ideally a fairly thin bore to get a more accurate impulse.
As @Communicator mentions re No.1 Cylinder location, also when cam cover was off, by looking at the lobes of the camshaft it would have been easy to confirm which cylinder was on firing stroke, one or four as the one that was firing would have both lobes pointing up away from the valves and you should be able to turn the shim buckets to feel clearance if applicable at the valves, the cylinder not firing out of one or four would have both lobes facing down, this is called "on the rock" as in one valve is just about closing and one is just about opening.
On a different note are you 100% sure all water out of the fuel system?
Glad you have located clearer timing marks now.
Re re the injection pump timing, as you say centralise the slot, then nip up the nuts to secure, after checking and sure injection timing correct tighten those pump nuts firmly and then slacken and retighten the injector pipes so they are not under strain from bending to a different position.
Another thing , if you are uncertain as to power to the solenoid electrics etc. then leave one battery terminal just loose enough to be able to yank off in a emergency until you are happy all round.

Hi

Thanks again and to Communicator for your help. Its a bit like Air Traffic Control talking to a novice in a plane when the pilot has fainted to get them to land! I have only rebuilt one engine before and this is my first diesel and I don't have a Haynes etc.

Before changing anything, i went this morning to try and see the position of the drop of fuel. I saw it first time, but then I started doing the turns v slowly to get some accuracy but there was no drop. I wonder whether i need to have ignition on to open the fuel feed - and i am not widely happy about turning the engine with ignition on in case it starts.
I can understand how the Swan Neck tool would be a lovely way to see exactly when tool is delivered.

As mentioned in previous posts, my working hypothesis is that the garage that worked on this engine previously who "got it to run for 5 minutes but then it stopped and wouldn't run again" didn't see the water in the fuel tank/feed and that some water may have been sitting in the fuel pump. This might explain the stickly valve. I am hoping that a flow of fresh diesel may help free it up.
The engine only ran a total of 15 - 20 seconds, and my releasing the fuel filter plug could not be the cause for it stopping. I like the idea of releasing the connectors to the injectors - i will have the appropriate spanner on hand next run.

I have double checked the valve positions, I think even 1 tooth either way would lead to piston/valve clash.

Regardless, as well as no coolant, i haven't put any of the covers on over the cambelt. I had a look at these, and i notice that the metal backing cover has a small hole about 2 o'clock, which must be for the timing. Having now got the timing to the point that the engine has run, I can now see:
1) holding the cover in place by hand, adding a mark on the gear through this hole, i can see it is diametrically opposite a "real" mark on the gear
2) there is a "real" mark on the fuel gear at 6 o'clock.

I have been assuming that Cylinder 1 is the one next to the cambelt and this is the one i should use to set my timing.
But now i am thinking that if I use the cylinder next to the gearbox for timing, this would lead to
1) the camshaft "real" mark showing through the hole and
2) the fuel gear mark being at 12 o'clock (i.e. "tdc").
I did read that the Citroen/Peugeot treat cylinder next to gearbox as cylinder 1 but google AI (!!) told me that my Fiat was the opposite.

If i took this new approach would mean that I could use "real" marks on all three gears, and have more precise ability to check their positions i.e.
1) crankshaft has its TDC mark
2) camshaft would be mark through the hole
3) fuel pump would be 12 o'clock (AND having just looked again at the cover, i can see a triangular imprint at this position which i think is marking this position).

So
1) I need to remove the camshaft gear in order to install the metal cover (which is annoying)
2) I see that the fuel pump is currently attached in a position which would allow me to turn it a tiny bit to advance it, but no retard. I will reposition the fuel pump in a middle position, which would allow a bit of movement in either direction. At least that way, i might be able to work out which direction is "better" and which is "worse".

And I presume i use the cylinder near the gearbox for timing?

Engine ignition will need to be on to open the solenoid valve to allow fuel to the injector pump. If you are worried about turning the engine whilst checking timing with ignition on, then slacken all four injector feeds, it only needs to be a little. The No.1 will still have it's fuel injection via the injection pump at that point and you can feel safe that the engine will not start. It's like pulling plug leads off a petrol engine, take one or two off and engine may keep running, but not with all off.
Note for any one else reading this, it is all for pre Common Rail diesel systems.!
You may be able to make a simple "Swan neck" tool using clear plastic tubing pushed onto the No.1 injector feed to check timing. ideally a fairly thin bore to get a more accurate impulse.
As @Communicator mentions re No.1 Cylinder location, as a general rule cam belt/timing chain end is No.1 cylinder but always a good idea to confirm in case of the odd exceptions to the rule. Also when cam cover was off, by looking at the lobes of the camshaft it would have been easy to confirm which cylinder was on firing stroke, one or four as the one that was firing would have both lobes pointing up away from the valves and you should be able to turn the shim buckets to feel clearance if applicable at the valves, the cylinder not firing out of one or four would have both lobes facing down, this is called "on the rock" as in one valve is just about closing and one is just about opening.
On a different note are you 100% sure all water out of the fuel system?
Glad you have located clearer timing marks now.
Re re the injection pump timing, as you say centralise the slot, then nip up the nuts to secure, after checking and sure injection timing correct tighten those pump nuts firmly and then slacken and retighten the injector pipes so they are not under strain from bending to a different position.
Another thing , if you are uncertain as to power to the solenoid electrics etc. then leave one battery terminal just loose enough to be able to yank off in a emergency until you are happy all round.

 

[bugsymike]

By the way if my replies are a bit hit and miss at present, I am having issues with internet connection and in process of changing to later version of Linux.
All this is in addition to "Anno Domini".

 

[sprie]

By the way if my replies are a bit hit and miss at present, I am having issues with internet connection and in process of changing to later version of Linux.
All this is in addition to "Anno Domini".

I am reasonably confident there is no water left in the system. I removed the fuel tank and thoroughly cleaned it inside and out. I have a new fuel filter. If there was any water left inside the pump, i am assuming it would have been flushed out by now.

Latest update:

I removed camshaft gear, attached the cambelt cover, reattached camshaft gear, and then set the belt so that 1) Crankshaft at TDC 2) camshaft has mark on gear visible in little hole in cover 3) fuel gear mark aligned with little triangle.
- engine started, ran MUCH quieter. When i took key out it stopped: total about 5 seconds
- left it a bit, did it again, engine started ok, little of clatter for a couple of seconds then settled running nicely, key out, DIDN'T STOP. Quickly undid the fuel connectors, needed 3 undone for it to stop. Ran about 15 seconds.

Don't know if this is relevant.
I do have a "code" light on my dash when i turn the ignition on, which then disappears - my keys don't have any electrical internals (it looks like they used to have a torch). I do have a little card with security codes on it, but i don't know if anything is needed to be done to reset anything.

I can't track down part diagram / number for the stop solenoid - not sure if this is an easy fix. Don't even know which photo below is the right component.

 

[Communicator]

I am reasonably confident there is no water left in the system. I removed the fuel tank and thoroughly cleaned it inside and out. I have a new fuel filter. If there was any water left inside the pump, i am assuming it would have been flushed out by now.

Latest update:

I removed camshaft gear, attached the cambelt cover, reattached camshaft gear, and then set the belt so that 1) Crankshaft at TDC 2) camshaft has mark on gear visible in little hole in cover 3) fuel gear mark aligned with little triangle.
- engine started, ran MUCH quieter. When i took key out it stopped: total about 5 seconds
- left it a bit, did it again, engine started ok, little of clatter for a couple of seconds then settled running nicely, key out, DIDN'T STOP. Quickly undid the fuel connectors, needed 3 undone for it to stop. Ran about 15 seconds.

Don't know if this is relevant.
I do have a "code" light on my dash when i turn the ignition on, which then disappears - my keys don't have any electrical internals (it looks like they used to have a torch). I do have a little card with security codes on it, but i don't know if anything is needed to be done to reset anything.

I can't track down part diagram / number for the stop solenoid - not sure if this is an easy fix. Don't even know which photo below is the right component.

The engine should stop almost instantaneously when ignition is switched off. I am wondering whether the solenoid operated fuel cut off, or stop valve, is physically stuck in the open position, but I hope not.

The relevant photo is number 2 (PXL_20250531_151215362), with the three wires disappearing into the pump.
Your key will have a coded electrinic chip inside the handle end. It does not require batteries or other components inside the key.
There is a black ring aerial around the ignition lock where you insert the key.. On switching the ignition on power is supplied to a code receiver located under the steering column. A power supplying radio pulse is sent from the receiver to the key via the aeriel ring. The key responds with its code signal. If the code matches one already stored in the code receiver the key code light is extinguished, almost simultaneously electronice on the pump have sent another code to the code receiver, which is only repeated back to the pump if the key has been recognised. When correct code, which changes each time, is received at the pump, the stop solenoid is energised to allow fuel injection.

To prevent hot wiring, the pump components are covered by a shield which is held onto the pump with security screws, so difficult to access the stop solenoid.

Look after the code card. It carries details of physical key, and an emergency code which can be used to start the engine if the code system fails.

To reach the stop solenoid you would have to grind out the security screws securing the shield. This would irrepairably damage the code system, so is drastic action. I suggest proving the fuel cut off valve is physically stuck first.

One way to do this could be to slacken all injector pipes, and disconnect the 3 way connector at the pump. When cranking the engine there should be no fuel dribbling from the loosened injector pipes.

I think that you can buy replacement stop solenoids from Ebay, but here is another source.

The quieter running of the engine is probably due to injection being less advanced than on earlier test. The other electrical connection to the pump is probably for the cold starting injection advance cancellation, which uses a wax capsule. I was going to link to the motor-roam website for their description, but that site is not working ATM.

 

[bugsymike]

It is a pity yours has the security cover over the stop solenoid, it means you can never be sure what is causing the fault.
At least the engine is running better than before.

 

[sprie]

It is a pity yours has the security cover over the stop solenoid, it means you can never be sure what is causing the fault.
At least the engine is running better than before.

The engine should stop almost instantaneously when ignition is switched off. I am wondering whether the solenoid operated fuel cut off, or stop valve, is physically stuck in the open position, but I hope not.

The relevant photo is number 2 (PXL_20250531_151215362), with the three wires disappearing into the pump.
Your key will have a coded electrinic chip inside the handle end. It does not require batteries or other components inside the key.
There is a black ring aerial around the ignition lock where you insert the key.. On switching the ignition on power is supplied to a code receiver located under the steering column. A power supplying radio pulse is sent from the receiver to the key via the aeriel ring. The key responds with its code signal. If the code matches one already stored in the code receiver the key code light is extinguished, almost simultaneously electronice on the pump have sent another code to the code receiver, which is only repeated back to the pump if the key has been recognised. When correct code, which changes each time, is received at the pump, the stop solenoid is energised to allow fuel injection.

To prevent hot wiring, the pump components are covered by a shield which is held onto the pump with security screws, so difficult to access the stop solenoid.

Look after the code card. It carries details of physical key, and an emergency code which can be used to start the engine if the code system fails.

To reach the stop solenoid you would have to grind out the security screws securing the shield. This would irrepairably damage the code system, so is drastic action. I suggest proving the fuel cut off valve is physically stuck first.

One way to do this could be to slacken all injector pipes, and disconnect the 3 way connector at the pump. When cranking the engine there should be no fuel dribbling from the loosened injector pipes.

I think that you can buy replacement stop solenoids from Ebay, but here is another source.

The quieter running of the engine is probably due to injection being less advanced than on earlier test. The other electrical connection to the pump is probably for the cold starting injection advance cancellation, which uses a wax capsule. I was going to link to the motor-roam website for their description, but that site is not working ATM.

Excellent information, many thanks

I did a test this morning as per your note. I released the connection to all four injectors and popped a paper towel under pipes:

1. Test 1: Ignition on, hand cranked engine. Blobs of fuel in turn from all four pipes
2. Test 2: Ignition off (but battery still connected). hand cranked engine. A small amount of fuel was released after I had turned the engine a lot – it appeared as a small drop, such that it didn’t drip off until I had turned it more: maybe ¼ of the fuel volume from test 1
3. Test 3: as per 2 but disconnecting the 3-wire connector: same results as 2

I am guessing this means that the stop valve is operating but not quite sealing.

I am thinking that before I rip it all open, I need to install the radiator/coolant so that there will be no harm from an over running engine.
I was also thinking of temporarily replacing the 12 cm length of fuel hose that connects to the fuel pump with a similar hose but where I install a fuel tap: that way I have an easy way to stop the engine during these tests without disconnecting the pipes. I suspect there will be a longer delay to engine stop as there will still be some fuel left in the pump, but I don’t see that being an issue once I have coolant.

I am wondering that if I can run the engine for 5-10 minutes, there is a chance all that fuel could flush the stop valve, and it might work properly.

Does that make sense?

 

[bugsymike]

Excellent information, many thanks

I did a test this morning as per your note. I released the connection to all four injectors and popped a paper towel under pipes:

1. Test 1: Ignition on, hand cranked engine. Blobs of fuel in turn from all four pipes
2. Test 2: Ignition off (but battery still connected). hand cranked engine. A small amount of fuel was released after I had turned the engine a lot – it appeared as a small drop, such that it didn’t drip off until I had turned it more: maybe ¼ of the fuel volume from test 1
3. Test 3: as per 2 but disconnecting the 3-wire connector: same results as 2

I am guessing this means that the stop valve is operating but not quite sealing.

I am thinking that before I rip it all open, I need to install the radiator/coolant so that there will be no harm from an over running engine.
I was also thinking of temporarily replacing the 12 cm length of fuel hose that connects to the fuel pump with a similar hose but where I install a fuel tap: that way I have an easy way to stop the engine during these tests without disconnecting the pipes. I suspect there will be a longer delay to engine stop as there will still be some fuel left in the pump, but I don’t see that being an issue once I have coolant.

I am wondering that if I can run the engine for 5-10 minutes, there is a chance all that fuel could flush the stop valve, and it might work properly.

Does that make sense?

Even with fuel solenoid closed correctly there may have been sufficient fuel in the pressure pipes for what you have seen, a few drips.
I would be wary of fitting extra shut off pipe in system as could be a source of air into fuel line in the future and cause added problems. the tiniest air bubbles can stop a diesel as it compresses the air rather than injecting the fuel.
Many diesel engine non/poor starting problems have been caused by air leaks at fuel filters and unions, etc.
With the coolant in the engine it will be safer to run engine to do further checks, not sure if it will do much re solenoid valve.
Insurance requirements dictate the fitting of immobilisers but from my perspective they tend to be a major cause of non starting as the vehicles get older.
Without it there and it's security shield , it would be easy to unscrew the fuel shut off solenoid, carefully ensuring the shut off pintle and spring comes out at the same time and then test / clean / replace as required.

 

[Communicator]

Even with fuel solenoid closed correctly there may have been sufficient fuel in the pressure pipes for what you have seen, a few drips.
I would be wary of fitting extra shut off pipe in system as could be a source of air into fuel line in the future and cause added problems. the tiniest air bubbles can stop a diesel as it compresses the air rather than injecting the fuel.
Many diesel engine non/poor starting problems have been caused by air leaks at fuel filters and unions, etc.
With the coolant in the engine it will be safer to run engine to do further checks, not sure if it will do much re solenoid valve.
Insurance requirements dictate the fitting of immobilisers but from my perspective they tend to be a major cause of non starting as the vehicles get older.
Without it there and it's security shield , it would be easy to unscrew the fuel shut off solenoid, carefully ensuring the shut off pintle and spring comes out at the same time and then test / clean / replace as required.

To be fair this was only suggested as a temporary measure. However I am not convinced that cutting the fuel supply to the pump will have the necessary speed of effect.

 

[sprie]

To be fair this was only suggested as a temporary measure. However I am not convinced that cutting the fuel supply to the pump will have the necessary speed of effect.

Good news and bad.

Good news
I attached the necessary parts of the coolant system.
I did have a leak when i filled, which i initially thought was from the water pump. But when i removed the steering pump, i could see it was coming from a short curved hose that led from the block to something behind the exhaust manifold. How on earth a rubber hose is supposed to cope with being 4cm from the exhaust manifold i cannot understand - no wonder it leaked. I have replaced it, and wrapped it in some heat shield to give it a chance.
Anyway, engine started well and ran nicely - revved freely. No leaks i can see.
Ran it for 5 minutes, pushed the pedal a bit.

Bad news
As you can guess, it wouldn't stop when i took the key out. Tried a few times. Had to stop it by releasing the injector hoses.

Communicator: you said "To reach the stop solenoid you would have to grind out the security screws securing the shield. This would irrepairably damage the code system, so is drastic action".

I can live without the immobiliser - the van is not worth much nowadays, and almost all of the time it won't be anywhere nickable. I also inherited a steering wheel lock.
Is it "just" a matter to drilling the screws out, finding my way to the stop solenoid, removing it, cleaning it and associated components and then replacing with new part?
If i take the cross members at the front plus radiator off, can you do this on the vehicle, or do i need to take the pump off again?

 

[bugsymike]

Good news and bad.

Good news
I attached the necessary parts of the coolant system.
I did have a leak when i filled, which i initially thought was from the water pump. But when i removed the steering pump, i could see it was coming from a short curved hose that led from the block to something behind the exhaust manifold. How on earth a rubber hose is supposed to cope with being 4cm from the exhaust manifold i cannot understand - no wonder it leaked. I have replaced it, and wrapped it in some heat shield to give it a chance.
Anyway, engine started well and ran nicely - revved freely. No leaks i can see.
Ran it for 5 minutes, pushed the pedal a bit.

Bad news
As you can guess, it wouldn't stop when i took the key out. Tried a few times. Had to stop it by releasing the injector hoses.

Communicator: you said "To reach the stop solenoid you would have to grind out the security screws securing the shield. This would irrepairably damage the code system, so is drastic action".

I can live without the immobiliser - the van is not worth much nowadays, and almost all of the time it won't be anywhere nickable. I also inherited a steering wheel lock.
Is it "just" a matter to drilling the screws out, finding my way to the stop solenoid, removing it, cleaning it and associated components and then replacing with new part?
If i take the cross members at the front plus radiator off, can you do this on the vehicle, or do i need to take the pump off again?

They are usually snap off security bolts holding the cover on and with engine in situ a bit of a bu**er to get at, maybe a dremal tool or similar, but be very careful not to damage Bosch pump it's self.
At the end what you would want to see is a bare solenoid with a single 12 volt supply that switches off with ignition key, so looking something like this pump in photo.
So just above the four outlets to the injectors is the brass looking solenoid with a single contact wire once all the security stuff is cleared away.
Bare in mind you may still need to check if actual solenoid is working or sticking, but security stuff still needs to be out the way to access it.
People do do them in situ, but it is a fiddle.

 

[Communicator]

If re

Good news and bad.

Good news
I attached the necessary parts of the coolant system.
I did have a leak when i filled, which i initially thought was from the water pump. But when i removed the steering pump, i could see it was coming from a short curved hose that led from the block to something behind the exhaust manifold. How on earth a rubber hose is supposed to cope with being 4cm from the exhaust manifold i cannot understand - no wonder it leaked. I have replaced it, and wrapped it in some heat shield to give it a chance.
Anyway, engine started well and ran nicely - revved freely. No leaks i can see.
Ran it for 5 minutes, pushed the pedal a bit.

Bad news
As you can guess, it wouldn't stop when i took the key out. Tried a few times. Had to stop it by releasing the injector hoses.

Communicator: you said "To reach the stop solenoid you would have to grind out the security screws securing the shield. This would irrepairably damage the code system, so is drastic action".

I can live without the immobiliser - the van is not worth much nowadays, and almost all of the time it won't be anywhere nickable. I also inherited a steering wheel lock.
Is it "just" a matter to drilling the screws out, finding my way to the stop solenoid, removing it, cleaning it and associated components and then replacing with new part?
If i take the cross members at the front plus radiator off, can you do this on the vehicle, or do i need to take the pump off again?

After removing the immobiliser cover, there is an electronic board with four wires, one of which will connect to the stop solenoid. The three incoming wire will include an ignition switched supply. Thiis wire needs to be identified, and reliably connected to the stop solenoid wire.

There are several threads on this forum relating to immobiliser removal, at least one includes useful photos. UnfortunatelyI cannot find a saved link.

 

[sprie]

They are usually snap off security bolts holding the cover on and with engine in situ a bit of a bu**er to get at, maybe a dremal tool or similar, but be very careful not to damage Bosch pump it's self.
At the end what you would want to see is a bare solenoid with a single 12 volt supply that switches off with ignition key, so looking something like this pump in photo.
So just above the four outlets to the injectors is the brass looking solenoid with a single contact wire once all the security stuff is cleared away.
Bare in mind you may still need to check if actual solenoid is working or sticking, but security stuff still needs to be out the way to access it.
People do do them in situ, but it is a fiddle.

as you might expect, i wasn't able to get the immobiliser off without damaging it - the security screws didn't want to come out.
Had a look at the stop solenoid - and there was nothing obvious but there is a small spring in there which i guess is responsible for pushing the stop part into the aperture and that might be tired, and the stop part might have some wear on it which wouldn't be apparent just looking at it. And the solenoid itself might have issues. No obvious wear in the pump aperture.
Replacement stop solenoid on order. So I am hoping that addresses the main issue.

As mentioned, i am happy to live without immobiliser (i have had issues with immobiliser on a car from the same era). I am hoping it is a matter of working out which of the the wires in the connector is the live one when ignition is on and sorting out a neat connection to the solenoid. Or do you think there is more complication?

 

[sprie]

as you might expect, i wasn't able to get the immobiliser off without damaging it - the security screws didn't want to come out.
Had a look at the stop solenoid - and there was nothing obvious but there is a small spring in there which i guess is responsible for pushing the stop part into the aperture and that might be tired, and the stop part might have some wear on it which wouldn't be apparent just looking at it. And the solenoid itself might have issues. No obvious wear in the pump aperture.
Replacement stop solenoid on order. So I am hoping that addresses the main issue.

As mentioned, i am happy to live without immobiliser (i have had issues with immobiliser on a car from the same era). I am hoping it is a matter of working out which of the the wires in the connector is the live one when ignition is on and sorting out a neat connection to the solenoid. Or do you think there is more complication?

Sorry, i have just seen you latest post which answers my last question i think.

 

[sprie]

small update: having taken the old Stop Solenoid off, i did a brief test with a test battery. The first two times i connected it, nothing happened. Third time, it activated and pushed the plunger. Whilst this is not proof, it does indicate that the issue was caused by a sticky solenoid. Hopefully, when the replacement arrives, I will be able to stop the engine.

Next question: whilst i can't do a proper test yet, I have a feeling that when i get the engine going, the "code" red warning light on the dashboard will stay on. I am wondering if there is a simple way to disable the light:
On the connector that went in the immobiliser
1) i am using the middle one to connect directly to the solenoid (as my test shows this has current when ignition is turned on)
2) i have sealed up the other 2 cables. I wonder whether there is something i can do with these which will suppress the warning light?

 

[bugsymike]

small update: having taken the old Stop Solenoid off, i did a brief test with a test battery. The first two times i connected it, nothing happened. Third time, it activated and pushed the plunger. Whilst this is not proof, it does indicate that the issue was caused by a sticky solenoid. Hopefully, when the replacement arrives, I will be able to stop the engine.

Next question: whilst i can't do a proper test yet, I have a feeling that when i get the engine going, the "code" red warning light on the dashboard will stay on. I am wondering if there is a simple way to disable the light:
On the connector that went in the immobiliser
1) i am using the middle one to connect directly to the solenoid (as my test shows this has current when ignition is turned on)
2) i have sealed up the other 2 cables. I wonder whether there is something i can do with these which will suppress the warning light?

Normally when powered up the solenoid magnet will draw the plunger /needle valve up allowing fuel into injector pump and on powering off the spring pushes the valve to close the fuel off.
When testing in your hand, if the needle is too far out the magnet may not have enough pull to draw it up.
Sorry I don't know about putting the red light out.