Engine cuts out 2.5D

[BF263]

Hi All,

Help needed! We bought a 1996 diesel auto 4wd last December (2014). 130,000km on the clock.
We've used it a couple of times but the last time we had issues with the engine cutting out.
For example after 50 miles of motorway we came to our exit. When we stopped at the roundabout the engine died. It restarted at the 2nd attempt and we continued. However this performance repeated itself for the remainder of our trip.
We found that by slipping into N and coasting to a halt we could keep the engine running with a little bit of throttle. Once I thought that the sediment light came on, and as we don't know when it was last serviced on our return I changed engine oil+filter, fuel filter and air filter. There was a small amount of muck in the sediment trap, but not much really.

Question: The workshop manual says that the fuel filter has a priming pump on top. Well ours doesn't. What dumbfounded me was that with an new (and empty) fuel filter it started on the first turn of the key. I was so surprised that I double checked the fuel route to the FIP did actually go through the filter.

Anyway a few short drives since reveal that the fault has not gone away.
Sometimes the engine doesn't die but the tick-over revs are lower than normal.
BTW the A/C was off and engine temp. is normal.

Has anyone else seen anything like this?

Any suggestions as to where I should look?

Thanks,
Martin.

[Simon Jones]

Some filter housings have the priming pump but most seem not to. Have you tried loosening the filler cap in case the breather is blocked and you are creating a vacuum as the fuel is sucked out.

[wonkanoby]

what about the little banjo filter thing on the pump itself

[rita]

Yes I would definitely have a look at the little banjo filter on top of the injector pump, there is also (should be ) a suction line filter in the tank.

Good luck.

PS what is the engine RPM when ticking over from Cold Start.

[Puma931]

I had exactly the same problem.
I replace the fuel filter and all has been good since (I still have the new banjo filter to fit as mine was missing).

[Northern Bongolow]

42-590A will be blocked in this drawing. its a little one way tank breather valve, its located on the inside of the drivers side chassis rail just between the tank and the fuel filter. it clips into a hole in the chassis, just pull it off, then remove from the end of the pipe and wash/clean it out and make sure its working by blowing through it gently.

http://lushprojects.com/bongopartsmk2/c ... mgno=.html

[BF263]

Thanks for the suggestions - just got in so it's too late to try anything tonight.
I'll give them a try tomorrow evening.
Rita asked about the cold tick-over - from memory about 800 rpm but will check and update tomorrow.
It's always been slower than the Peugeot XUD's that I'm more familiar with. But then it's bigger lump.

Thanks and regards,
Martin.

[BF263]

Hi Again,

Here's the update...

Cold tick-over 750 RPM. Pretty much the same when at normal temp.

I took off the fuel tank breather as suggested by Northern Bongolow.
While it was a bit mucky there was no blockage. I could blow or suck through it with no problem.
I cleaned it and put it back. Incidentally I could see no evidence of it being a one-way valve.

I also removed the banjo from top of the FIP. There was no filter in it and no sign of a blockage.

I removed the fuel line from the tank to the filter at the filter. I could blow back down this pipe and hear
bubbles in the tank so I don't think that it's blocked.

I did spot a split in the plastic pipe that takes the injector leak-off back to the rear of the FIP and return line.
Item 93-4104 on this diagram
http://lushprojects.com/bongopartsmk2/c ... mgno=.html

I renewed this pipe but I'm not convinced that this is the problem. Is this line under negative pressure?

Anyway, it's all back together. I'll drive it to work (with luck?) and see if there is any difference.

Anyone got any other suggestions for things to check??

Thanks in anticipation.
Martin.

[Simon Jones]

Worth trying to loosen the filler cap slightly anyway in case a vacuum is forming.

The leak-off pipe will be probably be under positive pressure but won't contain that much fuel unlike a common rail engine with electromechanical injectors.

Worth getting a new banjo filter (club shop) as this is the last line of defence to protect the FIP. The fact that they get blocked up means they are catching all the crud that would otherwise be clogging up and wearing away the pump and injectors.

[Northern Bongolow]

42-590A will be blocked in this drawing. its a little one way tank breather valve, its located on the inside of the drivers side chassis rail just between the tank and the fuel filter. it clips into a hole in the chassis, just pull it off, then remove from the end of the pipe and wash/clean it out and make sure its working by blowing through it gently.

http://lushprojects.com/bongopartsmk2/c ... mgno=.html

sorry my mistake.
look closely at the drawing you will see the little one way valve, it will be just inside the tube once the filter is removed.

[rita]

42-590A will be blocked in this drawing. its a little one way tank breather valve, its located on the inside of the drivers side chassis rail just between the tank and the fuel filter. it clips into a hole in the chassis, just pull it off, then remove from the end of the pipe and wash/clean it out and make sure its working by blowing through it gently.

http://lushprojects.com/bongopartsmk2/c ... mgno=.html

sorry my mistake.
look closely at the drawing you will see the little one way valve, it will be just inside the tube once the filter is removed.

Hi NB, cant get my head round this one, do you have any pics of the valve or other information why a Vapour valve would cause This vehicle to cut out while ticking over

[Northern Bongolow]

a few years ago at the bash i met a girl, no this isnt a love story . she had had the same persistent problem, the bongo would go great down the motorway for hours at a time, come up the slip road, revs off, and the bongo would stall at the give way. she had put the bongo in to several garages and had the pump seals done, new fuel lines, filters etc.
it turned out to be the tank breather system blocked so the tank was vacuuming, wash the cap out, that didnt work, checked the fuel filler nozzle at the 6 oclock position is a vent straight to the tank, cleaned this with a length of welding wire, it was blocked but still didnt sort it.
finally took off the little in line valve on the chassis washed out still not right, took off the little valve inside the line just before the vapour valve it was blocked, clean out and blow through, sorted.
that little ba**&&d cost hundreds of pounds to sort .

give it a try, nothing lost.

[rita]

a few years ago at the bash i met a girl, no this isnt a love story . she had had the same persistent problem, the bongo would go great down the motorway for hours at a time, come up the slip road, revs off, and the bongo would stall at the give way. she had put the bongo in to several garages and had the pump seals done, new fuel lines, filters etc.
it turned out to be the tank breather system blocked so the tank was vacuuming, wash the cap out, that didnt work, checked the fuel filler nozzle at the 6 oclock position is a vent straight to the tank, cleaned this with a length of welding wire, it was blocked but still didnt sort it.
finally took off the little in line valve on the chassis washed out still not right, took off the little valve inside the line just before the vapour valve it was blocked, clean out and blow through, sorted.
that little ba**&&d cost hundreds of pounds to sort .

give it a try, nothing lost.

Very strange indeed ,I have never heard of a Vapour Valve or PRV causing a vacuum in a Diesel fuel tank.

[Northern Bongolow]

take a close look at 42-590A in the drawing, the part that is next to it in the drawing looks like a small tube this is fitted inside the pipe to the tank, then the valve is fitted in the pipe end.

[BF263]

Hi all,
Well here's the next update..
After cleaning the plastic breather I drove to work and back (12.5 miles each way) with no problem.
On that basis we headed off on Friday for a weekend away, but once again after 50 or so miles on the motorway the engine stopped as we came to the roundabout at our exit.
Again it restarted OK but every junction/roundabout/traffic queue was a pain.
We stopped for a brew-up (well you do with a campervan ) and I slackened off the fuel tank cap.
There was no great sucking sound as it was loosened, but there was too much other noise to tell really.
Anyway all of the rest of the journey and all the return journey were without problem.

So when we got home I took the breather hose off. First I checked that the pipe back to the tank was clear.
NB is right. There's a little widget inside the tube. It's not a one-way valve though.
It offers a slight resistance to flow in both directions and comprises of two sprung-loaded balls.
It doesn't take much to actuate it. Just blow down the tube.
Being a bit more scientific I rigged up a U tube (nothing to do with videos on the Web) manometer using a bit of plastic tube and a T joint.
Using water as the indicating fluid the valve opened at a pressure of about 15 inches of water.
This is about 0.5 psi. It was pretty much identical in both directions.
Anyway I took the balls out and cleaned them re-assembled the whole lot and will test again shortly.
When I can get some pictures on the web I'll share them or do a factsheet if people think its worth it.

Regards,
Martin.