Technical Engine cuts out

[Keith1950]

Hi All
Hope for some advice.
Since the last time I used my fiat motorhome 3ltr 2007 , a problem has appeared Fault code P0230 which points to fuel relay primary circuit
The vehicle will start but runs for about 40 seconds then cuts out .
I have swapped the relay out for a known good one , but to as the fuel pump is running and priming the fuel injector pump would this not mean that the relay is activating for that 40 seconds and then the engine management is losing the signal to keep pump going , are there any other things that might switch of the fuel pump relay ?
I will be going out to check on relay voltage and activation on Sunday but NY help would be welcome
Regards
Keith

 

[bugsymike]

Hi All
Hope for some advice.
Since the last time I used my fiat motorhome 3ltr 2007 , a problem has appeared Fault code P0230 which points to fuel relay primary circuit
The vehicle will start but runs for about 40 seconds then cuts out .
I have swapped the relay out for a known good one , but to as the fuel pump is running and priming the fuel injector pump would this not mean that the relay is activating for that 40 seconds and then the engine management is losing the signal to keep pump going , are there any other things that might switch of the fuel pump relay ?
I will be going out to check on relay voltage and activation on Sunday but NY help would be welcome
Regards
Keith

May be unrelated, but some years ago I had a Fiat 1.3 Grande Punto that low pressure pump in tank was not working, found bridging the fuel pump relay using a fused link would activate it.
However the cause of the problem I located to a rotten wire a few mm from the ECU that is used to trigger that relay.
I had all the fuse box apart to follow the wire from the relay into the loom , across the bulkhead and up to the ECU.
The wire looked good until you pulled on the plastic and it "stretched" due to the break.

 

[Keith1950]

May be unrelated, but some years ago I had a Fiat 1.3 Grande Punto that low pressure pump in tank was not working, found bridging the fuel pump relay using a fused link would activate it.
However the cause of the problem I located to a rotten wire a few mm from the ECU that is used to trigger that relay.
I had all the fuse box apart to follow the wire from the relay into the loom , across the bulkhead and up to the ECU.
The wire looked good until you pulled on the plastic and it "stretched" due to the break.

Hi thanks for the reply , I'm guessing it's something to do with the ECU, leave it for a few minutes and it will start again , then cut out
Regards Keith

 

[bugsymike]

In my experience over the years ECUs get blamed and in the end it is often a £50 sensor.
The main time ECUs are involved is often due to an immobiliser issue related to wrong chipped keys etc.

 

[Keith1950]

had a mobile diagnostic check and no fault has been found so it was suggested that as both the low pressure and high pressure pumps were working fine it might be the leak off valve on the injectors , having disconnected the small rubber pipes on injector the diesel was coming out at a steady rate ,
my problem is trying to remove the rusty bolts and then the injectors themselves , i intend soaking with penetrating oil (or Coke )
but is there anything i should be careful with ( how much force can i use on the yolk bolt ( Impact wrench etc) any suggestions for a injector removal tool .
whats the best way of keeping any water out of the head whilst the injectors are being fixed ? ( i have siliconed the scuttle and added an extra aluminium chute to divert water )
and finally i will take note of which injector goes where but will they need to be recoded ?
its a Bosch EDC16C39 CF4/EOBD ACCORDING TO code reader .
i know its a long post
thanks in advance
Keith

 

[Kahcorp]

Running for 40sec then cutting out I doubt it's injectors. Removing (or trying to remove) could lead to a major cost.

 

[Anthony489]

Hi Keith

Your last post is ringing alarm bells

Injector removal is shied away from even by professional garages, who will farm it out to specialists The clamp bolts are renowned for snapping off, and even if that hurdle is overcome you need a hydraulic extractor capable of many tons of force to get the injectors out. Both these components have been sitting there corroding into place for nearly 20 years

It's bad enough if you are certain that the injectors are at fault, but your symptoms do not point to that at all. If you are getting a fault code, that can only be the result of the ECU sensing something wrong electrically, and injector performance issues don't fall into that category. I can't think of any mechanism that would make all 4 injectors decide to misbehave together after 40 miles, and even if they did the ECU could not sense that

The problem appears to me to be due to inadequate fuel pressure, which could have a number of causes (even a blocked filter).

Check first that the safety inertia switch has not been accidentally activated

I think the next step might be to connect a small 12 volt test lamp ( e.g. a sidelamp bulb ) across the lift (low pressure) pump terminals. As you know, the lift pump is in the top of the fuel tank under the floor cover between the seats. Then at least you can see if it is getting a reliable 12 volt supply.

Here is the description from eLearn:
The fuel pump relay T10 of junction unit B001 provides a direct battery power supply to the fuel pump N040 - pin 1 - along the line protected by fuse F21 of the engine compartment junction unit B001.

The coil is energized by pin 20 of connector B of the engine management junction unit M010; the coil for relay T10 receives a reference earth, via pin 11 of connector C of the engine compartment junction unit B001, coming from the NC contact for the inertia switch I050 (pin 3).

In the case of an impact the inertia switch opens, no longer supplying the reference earth to the coil for relay T10 and thereby interrupting the activation of the fuel pump N040 and the additional heating pump N044.

Beyond that, it's possible to connect a computer based diagnostic device such as MultiECUscan to the diagnostic connector, to monitor and store/graph fuel pressure and other parameters whilst driving around, which will help to narrow down the fault.

Good luck !

 

[Keith1950]

It's been diagnosed by RAC with their equiptment on site there are no fault codes stored , the amount of fuel coming from the leak off would fill a small container in mater of minutes,
So they need changing , the low pressure fuel pump is showing as ok The high pressure side is 450bar so that is fine .
Speaking to a fuel injection specialist he agrees that the syptoms are pointing towards faulty leak off valves ,
If the inertia switch was faulty the pump would not run , neither would the engine so I can rule that out
Thanks

 

[Keith1950]

Hi Keith

Your last post is ringing alarm bells

Injector removal is shied away from even by professional garages, who will farm it out to specialists The clamp bolts are renowned for snapping off, and even if that hurdle is overcome you need a hydraulic extractor capable of many tons of force to get the injectors out. Both these components have been sitting there corroding into place for nearly 20 years

It's bad enough if you are certain that the injectors are at fault, but your symptoms do not point to that at all. If you are getting a fault code, that can only be the result of the ECU sensing something wrong electrically, and injector performance issues don't fall into that category. I can't think of any mechanism that would make all 4 injectors decide to misbehave together after 40 miles, and even if they did the ECU could not sense that

The problem appears to me to be due to inadequate fuel pressure, which could have a number of causes (even a blocked filter).

Check first that the safety inertia switch has not been accidentally activated

I think the next step might be to connect a small 12 volt test lamp ( e.g. a sidelamp bulb ) across the lift (low pressure) pump terminals. As you know, the lift pump is in the top of the fuel tank under the floor cover between the seats. Then at least you can see if it is getting a reliable 12 volt supply.

Here is the description from eLearn:
The fuel pump relay T10 of junction unit B001 provides a direct battery power supply to the fuel pump N040 - pin 1 - along the line protected by fuse F21 of the engine compartment junction unit B001.

The coil is energized by pin 20 of connector B of the engine management junction unit M010; the coil for relay T10 receives a reference earth, via pin 11 of connector C of the engine compartment junction unit B001, coming from the NC contact for the inertia switch I050 (pin 3).

In the case of an impact the inertia switch opens, no longer supplying the reference earth to the coil for relay T10 and thereby interrupting the activation of the fuel pump N040 and the additional heating pump N044.

Beyond that, it's possible to connect a computer based diagnostic device such as MultiECUscan to the diagnostic connector, to monitor and store/graph fuel pressure and other parameters whilst driving around, which will help to narrow down the fault.

Good luck !

There is 450 bar on the high-pressure side so the low pressure pump must be running so ,as the inertia switch is either on or triped the engine would not run let alone for 40 seconds st a time or am I mistaken and the inertia switch resets itself ?
Regards

 

[Kahcorp]

Leak off will not stop your engine running.
You need to run Multiecuscan. There is good advice here once you have the correct data.
I have pulled quite as few injectors & I have lots of very good equipment. The Fiat injector removal can cost you a lot of money. It should be a last resort.

 

[Keith1950]

Leak off will not stop your engine running.
You need to run Multiecuscan. There is good advice here once you have the correct data.
I have pulled quite as few injectors & I have lots of very good equipment. The Fiat injector removal can cost you a lot of money. It should be a last resort.

just a quick question what would running a multiscan give me as opposed to a full diagnostic check done by the RAC using top of the range equiptment

 

[Keith1950]

Hi Keith

Your last post is ringing alarm bells

Injector removal is shied away from even by professional garages, who will farm it out to specialists The clamp bolts are renowned for snapping off, and even if that hurdle is overcome you need a hydraulic extractor capable of many tons of force to get the injectors out. Both these components have been sitting there corroding into place for nearly 20 years

It's bad enough if you are certain that the injectors are at fault, but your symptoms do not point to that at all. If you are getting a fault code, that can only be the result of the ECU sensing something wrong electrically, and injector performance issues don't fall into that category. I can't think of any mechanism that would make all 4 injectors decide to misbehave together after 40 miles, and even if they did the ECU could not sense that

The problem appears to me to be due to inadequate fuel pressure, which could have a number of causes (even a blocked filter).

Check

Beyond that, it's possible to connect a computer based diagnostic device such as MultiECUscan to the diagnostic connector, to monitor and store/graph fuel pressure and other parameters whilst driving around, which will help to narrow down the fault.

Good luck !

As the engine only runs for 40 seconds ( not 40 Miles) i don't think i can drive around to narrow fault down
Low pressure pump is running enough to supply fuel to high pressure pump which is running at 450 bar until engine cuts out , then fault reoccurs
thanks

 

[Anthony489]

I agree that excessive leakoff is not desirable. However, the LP and HP pump should be quite capable of delivering 0.3 litres per minute when the engine is running at full power. Unless the leakoff is so enormous that you are losing all pressure, the engine will still run. If it dips below a certain threshold (150 Bar ?) the ECU will cut off the electrical pulses to the injectors to protect the engine and this will trigger fault codes.

It's hard to see how having the van standing has caused an injector problem, they won't have been subject to any wear when not running.

I don't know the current capabilities of the RAC diagnostic tool, but as an "all makes" tool it's possible that it cannot test to the depth of Fiat's own tool or MultiECUscan. Maybe someone else can confirm.

I fear that you could enter a world of pain getting the injectors replaced and recoded, only to find that the original fault remains.

 

[bugsymike]

I agree with the advice you have been given.
RAC diagnostics are not the same as a professional who specialises on locating vehicle electronic faults and have recourse to a lot more data than someone who covers a wide range of breakdown failures from a puncture to a full blown engine failure requiring a recovery to their approved dealer etc.
I would see if something like a full version of MES or a good professional tool like Like Snap On Zeus etc. read the live data as the engine is cranked.
It would be interesting to see Common Rail pressure readings, from a minimum at cranking of around 230 Bar, over 300Bar at idle and a steady climb as revs increased to roughly 1600-2000Bar at higher revs.
Also the readings on the individual injectors mls and % etc.
As has been advised, at this stage no need to try and yank out injectors with all the associated problems possible.
A leak off test measuring the return from each injector can give a quick and cheap guide without dismantling.
Incidentally as you say it runs and then dies, do you have any aftermarket immobiliser system cutting off fuel, as factory one usually once engine running would not allow it to cut out for safety reasons.
High pressure pump fuel regulators can cause problems as can return filter blockages, but I would expect good quality live data diagnostics would show this.
It's very easy to put loads of new parts on a vehicle trying to chase a fault and spend £1000s with a non runner still at the end, as I am sure others on the Forum can testify after taking to Fiat Main Dealers etc.
Basically fault diagnosis is only as good as the person using the tools.
I thought I knew a fair amount after over 55 years in the Motor trade, but there is always somethings that a couple of hours of labour by a dedicated specialist can pick up that has been missed. That is why the Motor trade will reluctantly on the odd occasion go to those specialists even though they begrudge the cost.
With engine I assume starting like normal and then dying, it would tend to indicate some form of fuel restriction, possibly prior to the high pressure pump.
I had one vehicle problem that I ran a clean gravity feed can directly to the the high pressure pump bypassing the filters and existing fuel lines etc. and was able to locate an issue with a fuel line that others had missed. Note, that sort of test can only run for a short while as a five litre can soon runs out when the diesel return is going back to the original main fuel tank.

 

[Keith1950]

I agree that excessive leakoff is not desirable. However, the LP and HP pump should be quite capable of delivering 0.3 litres per minute when the engine is running at full power. Unless the leakoff is so enormous that you are losing all pressure, the engine will still run. If it dips below a certain threshold (150 Bar ?) the ECU will cut off the electrical pulses to the injectors to protect the engine and this will trigger fault codes.

It's hard to see how having the van standing has caused an injector problem, they won't have been subject to any wear when not running.

I don't know the current capabilities of the RAC diagnostic tool, but as an "all makes" tool it's possible that it cannot test to the depth of Fiat's own tool or MultiECUscan. Maybe someone else can confirm.

I fear that you could enter a world of pain getting the injectors replaced and recoded, only to find that the original fault remains.

as i said the leakoff is enough to fill a sample bottle in a couple of mins , probably more than it uses to run the engine , so i would guess that the ecu is seeing lots of diesel flowing thru but the mass airflow is not seeing enough air so ecu decides that mixture balance is way to rich and cuts engine
thanks

 

[Keith1950]

I agree with the advice you have been given.
RAC diagnostics are not the same as a professional who specialises on locating vehicle electronic faults and have recourse to a lot more data than someone who covers a wide range of breakdown failures from a puncture to a full blown engine failure requiring a recovery to their approved dealer etc.
I would see if something like a full version of MES or a good professional tool like Like Snap On Zeus etc. read the live data as the engine is cranked.
It would be interesting to see Common Rail pressure readings, from a minimum at cranking of around 230 Bar, over 300Bar at idle and a steady climb as revs increased to roughly 1600-2000Bar at higher revs.
Also the readings on the individual injectors mls and % etc.
As has been advised, at this stage no need to try and yank out injectors with all the associated problems possible.
A leak off test measuring the return from each injector can give a quick and cheap guide without dismantling.
Incidentally as you say it runs and then dies, do you have any aftermarket immobiliser system cutting off fuel, as factory one usually once engine running would not allow it to cut out for safety reasons.
High pressure pump fuel regulators can cause problems as can return filter blockages, but I would expect good quality live data diagnostics would show this.
It's very easy to put loads of new parts on a vehicle trying to chase a fault and spend £1000s with a non runner still at the end, as I am sure others on the Forum can testify after taking to Fiat Main Dealers etc.
Basically fault diagnosis is only as good as the person using the tools.
I thought I knew a fair amount after over 55 years in the Motor trade, but there is always somethings that a couple of hours of labour by a dedicated specialist can pick up that has been missed. That is why the Motor trade will reluctantly on the odd occasion go to those specialists even though they begrudge the cost.
With engine I assume starting like normal and then dying, it would tend to indicate some form of fuel restriction, possibly prior to the high pressure pump.
I had one vehicle problem that I ran a clean gravity feed can directly to the the high pressure pump bypassing the filters and existing fuel lines etc. and was able to locate an issue with a fuel line that others had missed. Note, that sort of test can only run for a short while as a five litre can soon runs out when the diesel return is going back to the original main fuel tank.

As I said the leak off is a steady stream from return pipe ,

 

[bugsymike]

as i said the leakoff is enough to fill a sample bottle in a couple of mins , probably more than it uses to run the engine , so i would guess that the ecu is seeing lots of diesel flowing thru but the mass airflow is not seeing enough air so ecu decides that mixture balance is way to rich and cuts engine
thanks

If you are measuring the return from all the leak off pipes and the return from the high pressure pump it's self you will find it is quite a high normal volume.
Go online and see the readings people get in measured jars when doing "leak off test" on individual injectors.
However, generally if excessive leak off, even only from one injector , then the vehicle will not even try to start on modern Common Rail Systems as it stops it from reaching the roughly 230 Bar min. that the ECU will need to turn on the signal to the injectors.
In the old days it was possible two undo to injector feed pipes and an engine would still continue to run, where as modern Common Rail Systems even the tiniest leak at one union and it will not even try to fire.
Some now run at 2500Bar (36000 psi) where as the old injector systems ran happily at 175Bar.
Note even that 175Bar fine spray was enough to punch holes in a sheet of A4 paper and will easily go through your skin causing major visit to NHS as my College Lecturer told us back in 1970, so keep away from any fine diesel "mist".

 

[bugsymike]

One other small thought, many years ago I did a clutch job and went to start the vehicle, which it did straight away, however it cut out after a few seconds every time.
The fault was an oil pressure switch wire that had become dislodged, so ECU was checking for oil pressure then shutting down the engine.
Others on Forum may have more knowledge if this is a possibility on your vehicle.