the hobbler
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Hi Andrew; Steve Gurney will contact you direct, but I will also send you his details on a private e-mail. Hope this helps you sort your problem out.
Technical Starting (not!) again
- Thread starter AndrewRL
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Technical Starting (not!) again
AndrewRL
Member
Thanks all...very humbling
AndrewRL
Member
So a bit of an update (and a continued plea for suggestions )...
Steve kindly came round on Sunday and had a look. I had on Saturday tried the other suggestions (e.g. checking for leaks round the carb) but with no luck. We identified/cured some issues but are sadly now with an engine that won't fire at all.
The initial difficulty starting, rough running and refusal to rev was quickly identified as the engine running on only one cylinder (oops...am I bad!). Below is a summary of Sunday (mainly provided from Steve):
So we started with it firing on one cylinder.
Identified this as not getting good spark out of one of the distributor outputs.
Pulled apart an ht lead in all the swapping.
Replaced ht leads and distributor cap and it initially ran ok, but then faltered when out for a drive.
Pushed it back...fortunately we had only driven ~400m
No spark, so cleaned out the distributor cap, ran ok for 5+ minutes, but air bubbles in fuel pipe from pump noticed and then it spluttered again and died. No spark again.
Fully cleaned distributor
Seemingly good spark, but now it won’t start again.
Below is a link to a video of the air bubbles in the fuel pipe...does anyone know the cause (or impact of this)? Despite the bubbles, fuel did seem to be getting up to the carb. We tightened the pump securing bolts and think this reduced the volume of bubbles but can't quite get our heads round where the air was coming in.
[ame]https://youtu.be/EkgQYSczRpE[/ame]
So we have ended up with an engine that turns over OK, seems to have fuel getting to the carb OK but now just won't fire! It did run fine for a while so don't think there is an air, tappets or timing issue (but who knows ). I left it for a while in case the carb was flooded but still no joy. I've plugged the battery in and am going to leave it until Tuesday evening and try and check the state of the plugs (in case they got all fouled with the other issues) and try again; if no luck I'll have a look in the carb to see how full the float is.
So, apart from the general "any suggestions?" question, can I ask for advice on a few things:
(a) if the carb floods - how do you "unflood it"? Just leave it? Take the top off and mop out the fuel? Drain it (via the main jet?)?
(b) how tight is your distributor cap? Do the clips hold it really tight or is there some (small) movement possible?
(c) how critical is the exact spacing of the fuel pump? The new spacer seems a fraction thinner than the old one. Does a difference of probably less than 1mm make any difference to the force/volume of the fuel pumped?
Sorry. Lots of questions there which may be better spread across different posts but I don't want to overwhelm the forum!!
Many thanks for your continued patience.
)...Steve kindly came round on Sunday and had a look. I had on Saturday tried the other suggestions (e.g. checking for leaks round the carb) but with no luck. We identified/cured some issues but are sadly now with an engine that won't fire at all.
The initial difficulty starting, rough running and refusal to rev was quickly identified as the engine running on only one cylinder (oops...am I bad!). Below is a summary of Sunday (mainly provided from Steve):
So we started with it firing on one cylinder.
Identified this as not getting good spark out of one of the distributor outputs.
Pulled apart an ht lead in all the swapping.
Replaced ht leads and distributor cap and it initially ran ok, but then faltered when out for a drive.
Pushed it back...fortunately we had only driven ~400m
No spark, so cleaned out the distributor cap, ran ok for 5+ minutes, but air bubbles in fuel pipe from pump noticed and then it spluttered again and died. No spark again.
Fully cleaned distributor
Seemingly good spark, but now it won’t start again.
Below is a link to a video of the air bubbles in the fuel pipe...does anyone know the cause (or impact of this)? Despite the bubbles, fuel did seem to be getting up to the carb. We tightened the pump securing bolts and think this reduced the volume of bubbles but can't quite get our heads round where the air was coming in.
[ame]https://youtu.be/EkgQYSczRpE[/ame]
So we have ended up with an engine that turns over OK, seems to have fuel getting to the carb OK but now just won't fire! It did run fine for a while so don't think there is an air, tappets or timing issue (but who knows
). I left it for a while in case the carb was flooded but still no joy. I've plugged the battery in and am going to leave it until Tuesday evening and try and check the state of the plugs (in case they got all fouled with the other issues) and try again; if no luck I'll have a look in the carb to see how full the float is.So, apart from the general "any suggestions?" question, can I ask for advice on a few things:
(a) if the carb floods - how do you "unflood it"? Just leave it? Take the top off and mop out the fuel? Drain it (via the main jet?)?
(b) how tight is your distributor cap? Do the clips hold it really tight or is there some (small) movement possible?
(c) how critical is the exact spacing of the fuel pump? The new spacer seems a fraction thinner than the old one. Does a difference of probably less than 1mm make any difference to the force/volume of the fuel pumped?
Sorry. Lots of questions there which may be better spread across different posts but I don't want to overwhelm the forum!!
Many thanks for your continued patience.
From what I could see you have a lot of bubbles but they only seem to be in the pipe from the pump?
If that's the case you have an air leak which is pulling air into the fuel line. Probably either loose pipe of faulty pump.
The spacer behind the pump is fairly crucial. If the rod protruding is too small then you will get minimal movement on the pump arm. The same goes for it being too long as this will again reduce the amount the arm can travel causing lower fuel pressure and possibly damaging the pump.
By the looks of the fuel being passed through the hose I don't think this is an issue but I would try and sort the bubble problem out.
Have you checked the float in the carb? if you put it in a jar of fuel does it sink or float? if it sinks it has a hole in it and wont work. If its a brass one you can solder it.
Also check the level is correct otherwise it will cause the carb to flood.
If that's the case you have an air leak which is pulling air into the fuel line. Probably either loose pipe of faulty pump.
The spacer behind the pump is fairly crucial. If the rod protruding is too small then you will get minimal movement on the pump arm. The same goes for it being too long as this will again reduce the amount the arm can travel causing lower fuel pressure and possibly damaging the pump.
By the looks of the fuel being passed through the hose I don't think this is an issue but I would try and sort the bubble problem out.
Have you checked the float in the carb? if you put it in a jar of fuel does it sink or float? if it sinks it has a hole in it and wont work. If its a brass one you can solder it.
Also check the level is correct otherwise it will cause the carb to flood.
Duffys Dad
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This is really turning into a saga. From what you say twice you had no spark so to me this is looking more like an ignition issue than fuel. Do you have spare new or old points, plugs, condenser, distributor cap and HT leads you can swap. Just change one thing at a time to see if we can eliminate the trouble maker. Keep trying it will be worth it when you do find and solve the issue.
Andrew,
Oh dear, your car certainly seems to be giving you the run around!
As Duffy's Dad suggests, best to only change one thing at a time.
To answer some of your latest questions :-
There's a difference between the engine flooding and the carb. flooding.
If there's no spark, the engine gets flooded with unburnt fuel.
If the carb. floods, it means that the float valve is not shutting off the fuel when the fuel level in the float chamber is at the correct level to supply fuel through the jets. If this happens, the engine might still continue to run but very lumpily and emit black smoke from the exhaust and then cut out. Often there's a smell of fuel from the engine bay and exhaust. Also if the carb is flooding, there might be signs of fuel leaking down the carb. body below the gasket under the carb. top cover and also in the drip tray under the carb. and out any drain pipe (if fitted) to the drip tray. (this drip tray may be part of the plastic? spacer/insulator block iirc).
If the engine floods, it will dry out in time by itself. Alternatively, remove the spark plugs, spin the engine over, dry and refit the plugs.
I think it important at this stage to ascertain if you have an ignition problem, a fuel problem, or both.
I'd start with the ignition system. If you pull the ht lead from the coil to the distributor cap and position the distributor cap end of the lead about 1/4inch (6mm) from an engine earth point (e.g. cylinder head), spin the engine on the starter, you should get a strong spark at regular intervals. I suspect that you might have a faulty plug lead. You could try swapping over the plug leads (if they are long enough) and see if the non-sparking switches to the other cylinder. If they are suppressed leads, I'd be especially wary and prefer to change them if they're old.
Another trick to check plug leads etc. is to spin the engine over or if possible start and run the engine in complete darkness - what you'll be watching for is stray sparks/blue flashes which indicate the ht voltage is jumping to earth instead of firing the plugs. There shouldn't be any blue flashes if everything is ok.
If the problem of non-sparking is confined to one cylinder - you can rule out points, condenser, coil and low tension circuit. Instead, concentrate on plugs, plug leads (but not coil ht lead) and possibly distributor cap.
Low compression pressure on 1 cylinder can result in a misfire or indeed no firing on that cylinder but as your engine sometimes runs ok, I think you can rule this out , unless you've recently adjusted the valve clearances (tappets) too tightly.
Distributor cap clips too loose? The cap should ideally be held firmly in place by the clips. Often there's a locating notch on the distributor body that the cap engages with to resist moving. I don't think that a loose cap is the cause of your problems, but do carefully check the cap inside and outside including inside the ht cable sockets, for signs of 'tracking' - fine spidery lines of carbon caused by the ht voltage shorting to earth inside of firing the plug. If cleaning the cap, don't scratch the surfaces as this can promote 'tracking' as can dirt build-up.
As regards the air bubbles in the fuel line, many on here have reported the same occurance but while it's undesirable, they don't seem to adversly affect engine running. I'd make sure there's no points where air could be drawn in.
Fuel pump? I don't have any info on checking/setting the pump stroke so I can't advise on this. I'm sure others on here could help if required. My approach would be to run an independent fuel supply (as I detailed in an earlier post) if I had any doubts about the adequacy of the fuel supply or pump pressure.
Don't give up, I'm sure you'll soon figure out what the problem is.
AL.
Oh dear, your car certainly seems to be giving you the run around!
As Duffy's Dad suggests, best to only change one thing at a time.
To answer some of your latest questions :-
There's a difference between the engine flooding and the carb. flooding.
If there's no spark, the engine gets flooded with unburnt fuel.
If the carb. floods, it means that the float valve is not shutting off the fuel when the fuel level in the float chamber is at the correct level to supply fuel through the jets. If this happens, the engine might still continue to run but very lumpily and emit black smoke from the exhaust and then cut out. Often there's a smell of fuel from the engine bay and exhaust. Also if the carb is flooding, there might be signs of fuel leaking down the carb. body below the gasket under the carb. top cover and also in the drip tray under the carb. and out any drain pipe (if fitted) to the drip tray. (this drip tray may be part of the plastic? spacer/insulator block iirc).
If the engine floods, it will dry out in time by itself. Alternatively, remove the spark plugs, spin the engine over, dry and refit the plugs.
I think it important at this stage to ascertain if you have an ignition problem, a fuel problem, or both.
I'd start with the ignition system. If you pull the ht lead from the coil to the distributor cap and position the distributor cap end of the lead about 1/4inch (6mm) from an engine earth point (e.g. cylinder head), spin the engine on the starter, you should get a strong spark at regular intervals. I suspect that you might have a faulty plug lead. You could try swapping over the plug leads (if they are long enough) and see if the non-sparking switches to the other cylinder. If they are suppressed leads, I'd be especially wary and prefer to change them if they're old.
Another trick to check plug leads etc. is to spin the engine over or if possible start and run the engine in complete darkness - what you'll be watching for is stray sparks/blue flashes which indicate the ht voltage is jumping to earth instead of firing the plugs. There shouldn't be any blue flashes if everything is ok.
If the problem of non-sparking is confined to one cylinder - you can rule out points, condenser, coil and low tension circuit. Instead, concentrate on plugs, plug leads (but not coil ht lead) and possibly distributor cap.
Low compression pressure on 1 cylinder can result in a misfire or indeed no firing on that cylinder but as your engine sometimes runs ok, I think you can rule this out , unless you've recently adjusted the valve clearances (tappets) too tightly.
Distributor cap clips too loose? The cap should ideally be held firmly in place by the clips. Often there's a locating notch on the distributor body that the cap engages with to resist moving. I don't think that a loose cap is the cause of your problems, but do carefully check the cap inside and outside including inside the ht cable sockets, for signs of 'tracking' - fine spidery lines of carbon caused by the ht voltage shorting to earth inside of firing the plug. If cleaning the cap, don't scratch the surfaces as this can promote 'tracking' as can dirt build-up.
As regards the air bubbles in the fuel line, many on here have reported the same occurance but while it's undesirable, they don't seem to adversly affect engine running. I'd make sure there's no points where air could be drawn in.
Fuel pump? I don't have any info on checking/setting the pump stroke so I can't advise on this. I'm sure others on here could help if required. My approach would be to run an independent fuel supply (as I detailed in an earlier post) if I had any doubts about the adequacy of the fuel supply or pump pressure.
Don't give up, I'm sure you'll soon figure out what the problem is.
AL.
Everyone here is incredibly helpful and far more learned than I, however I may just throw in the experience I had with an ignition issue that made me and a fiat buddy almost pull out our hair. A car that had fired well previously, but after some fiddling suddenly would not.
Tried all the above yet it ended up being the oil filler dipstick touching the condenser. It was grounding the circuit and causing ignition to fail.
Such a simple problem but one not easily spotted! Not sure if later models have an all metal dipstick or not
Tried all the above yet it ended up being the oil filler dipstick touching the condenser. It was grounding the circuit and causing ignition to fail.
Such a simple problem but one not easily spotted! Not sure if later models have an all metal dipstick or not
Well, it’s certainly ignition related that needs fixing first. As Andrew stated, it was only firing on one cylinder.
This was localised to the RHS output of the distributor. The leads were eliminated by swapping. However, when pulling off leads to try a new cap, one of the leads disintegrated. So I need to head home to pick up a new set.
New set fitted and it ran ok. So we went for a test drive. Didn’t last long, and diagnosed issue as no spark. Noticed that newly fitted cap was oily, so cleaned cap and it ran ok for over 5 min, when I took the video, but spluttered and stopped.
I checked and there was no spark, so I decided to give distributor and cap a good clean with a towel, but then it still wouldn’t start. Tested and had spark jumping 1cm on both leads so assumed ok. Engine wouldn’t start, so concluded that it may be flooded and decided to try it again later. Andrew tried it later after a few hours, but it still wouldn’t start.
Maybe in our last bout of distributor cleaning, I put the leads back on the wrong way around, and this is why it won’t start when it has good spark. If it is this, at least it’s easy fix.
Andrew is away for a few days, so we’ll have to wait until next week to look at it again.
cheers, Steve
This was localised to the RHS output of the distributor. The leads were eliminated by swapping. However, when pulling off leads to try a new cap, one of the leads disintegrated. So I need to head home to pick up a new set.
New set fitted and it ran ok. So we went for a test drive. Didn’t last long, and diagnosed issue as no spark. Noticed that newly fitted cap was oily, so cleaned cap and it ran ok for over 5 min, when I took the video, but spluttered and stopped.
I checked and there was no spark, so I decided to give distributor and cap a good clean with a towel, but then it still wouldn’t start. Tested and had spark jumping 1cm on both leads so assumed ok. Engine wouldn’t start, so concluded that it may be flooded and decided to try it again later. Andrew tried it later after a few hours, but it still wouldn’t start.
Maybe in our last bout of distributor cleaning, I put the leads back on the wrong way around, and this is why it won’t start when it has good spark. If it is this, at least it’s easy fix.
Andrew is away for a few days, so we’ll have to wait until next week to look at it again.
cheers, Steve
Hi Steve,
I'd like to commend you for calling round to Andrew's to try to help out. Well Done!
Another few points for Andrew to consider, on his return :-
If oil got into the distributor cap, don't forget to check that the contact breaker points faces are still clean. (How did the oil get in there?)
Ensure the centre earth contact inside the distributor is intact and free to move (iirc, it's spring-loaded).
Have a look at the rotor arm. If it's the type with a built-in resistor (some Fiats had these, back in the day) be very careful, they sometimes failed. Check all over the rotor arm, I've seen them with tracking underneath (i.e. shorting to earth)! To check for a faulty rotor arm - turn the engine to where the points are closed, distributor cap off, turn on ignition, hold HT lead from the coil to the distributor approx. 6mm from the centre of the rotor arm, briefly flick open the points with a small screwdriver, there should NOT be a spark between the HT lead and the rotor arm. If there is the rotor arm is faulty.
While in the distributor, check that the low tension lead/s from the coil to the distributor and also from the condenser to the same point are in good condition.
None of the above points would cause the engine to run on only one cylinder but I mention them as they are worth checking/discounting as you go through the fault-finding process in order to get the ignition system into a good operating condition before checking out the fuel system/carburettor.
AL.
I'd like to commend you for calling round to Andrew's to try to help out. Well Done!
Another few points for Andrew to consider, on his return :-
If oil got into the distributor cap, don't forget to check that the contact breaker points faces are still clean. (How did the oil get in there?)
Ensure the centre earth contact inside the distributor is intact and free to move (iirc, it's spring-loaded).
Have a look at the rotor arm. If it's the type with a built-in resistor (some Fiats had these, back in the day) be very careful, they sometimes failed. Check all over the rotor arm, I've seen them with tracking underneath (i.e. shorting to earth)! To check for a faulty rotor arm - turn the engine to where the points are closed, distributor cap off, turn on ignition, hold HT lead from the coil to the distributor approx. 6mm from the centre of the rotor arm, briefly flick open the points with a small screwdriver, there should NOT be a spark between the HT lead and the rotor arm. If there is the rotor arm is faulty.
While in the distributor, check that the low tension lead/s from the coil to the distributor and also from the condenser to the same point are in good condition.
None of the above points would cause the engine to run on only one cylinder but I mention them as they are worth checking/discounting as you go through the fault-finding process in order to get the ignition system into a good operating condition before checking out the fuel system/carburettor.
AL.
El cargador
Member
Franko I have a diesel Ford focus which had a running problem , one thing I questioned was a large amount of air bubbles coming from the fuel pump to the injectors I was told this was normal. Different system I know but I thought If it's a closed system where do the bubbles come from.
" Well, this theory that I have--that is to say, which is mine-- " (Anne Elk....Monty Python)
my theory is that these are often not actually air at all but are fuel vapour bubbles with nowhere to go; especially likely in a hot engine-bay.
I'm just wondering if this is an example of what I think is called 'cavitation' in the fuel pump.
I believe if e.g. in an engine oil pump, if the oil entering the pump is restricted, then cavitation can occur, i.e. bubbles can appear in the output as if from nowhere. Engine bearings don't like to be fed with oil containing bubbles or frothy oil. Carbs probably don't like bubbly fuel either.
As far as I can see, there doesn't appear to be any bubbles in the fuel line going to the filter or in the short fuel line from filter to pump, but lots of bubbles in the line from pump to carb. Looking at the filter pipe stubs, they appear to be a lot smaller than the inside bore of the fuel pipes/liners. So I'm wondering if there isn't effectively a restriction in the flow caused by these filter pipe stubs on the feed side of the pump compared to the outlet side.
I've always been led to believe that a fuel filter should be fitted after the pump, i.e. on the pressure side.
Maybe try temporarily by-passing the fuel filter with a length of hose and see if the bubbles then disappear in the fuel line from pump to carb ?
I do recall others on here in the past asking about fuel lines and filters fitted on the pressure side of the pump not being full of fuel. Idt we reached any conclusions or found solutions to this phenomenon.
AL.
