diesel stalls after 30 seconds

[pvmw]

I thought I'd see if the hive mind can help. I've looked and not found a thread that reflects my symptoms.......

Van is a 1990 Mk 5 camper conversion but its a bit of a mongrel having an ex post office diesel engine fitted to replace the original petrol one many years ago. It hasn't had much use recently and has been parked up since last year. When parked up it would start pretty well instantly and tickover for ever, Last week I fired it up, it ran for a quite a while (not sure how long because I left it ticking over and when I returned it had stopped). I assumed it was out of fuel so stuck in a couple of gallons I wouldn't start so I assumed air in the system ((I've run out once before and had to bleed the system), loosened the injectors and cranked it over until diesel coming out of all unions. Tightened them up and it fired instantly and ran for about 30 seconds before dying. Loosened injectors again and no diesel coming out so bled the system again and re-tightened them. Same result. 30 seconds of running then splutters to a halt and no diesel at injectors.

We are thinking possibly a pipe in fuel system has perished while its been sitting and it is drawing air into system. Is this likely, and if so what is likely to be the culprit? While it is running and until it looses fuel it appears to run fine so it has to be a fuelling problem.

I don't want to scrap it and be reduced to living in a tent (I hate tents), can anyone suggest what we might try to identify a possible problem

[metalworker0]

will assume its a 2.5
follow the thread below this one he has similar issues

viewtopic.php?f=2&t=237083

all the best.mark

[pvmw]

I think its time for an update................
someone explain this - I can't!

I've had the van about 10 years. The previous owner (who was an MOT inspector) bought it for his parents, was appalled by the fuel consumption (it was petrol) so converted it to diesel, fitted power steering and various other mods - at which point his mother took one look at it and turned it down (this history is vaguely relevant) so he sold it to me.

It doesn't get much use so has been parked up. MOT time so I went to start it - and it would run for about 20 secs. and then die. We thought it was out of diesel so put a few gallons in and bled the system = it ran for about 30 secs. and died. It was suggested that the lift pump was faulty so I fitted a replacement (also replacing the connectors with hoses and jubilee clips). It ran for 30 secs. and died. Identified that there was no diesel getting to injectors.

Long story short. We checked fuel lines, and blowing into the line from tank to lift pump heard no sound of bubbling. However, when blowing into the return pipe to the tank we heard bubbling in fuel. It seems hard to believe, but we swapped the outlet and return pipes (previous owner had conveniently put quick release connectors in fuel lines - unless that is standard) and, unbelievably, the old thing started instantly (it was always a good starter) and ran perfectly. Even the flat spot it used to have has gone and it appears to rev better.

It would appear that when he installed the engine he got the supply and return pipes from the tank switched and for the last 10+ years the lift pump has been drawing fuel via the return - is that even possible? Important thing is it now runs (all I need is an MOT) but I'm having trouble getting my head around the fact it has been working like this for the last 10 years. I'd love to hear anyone's comments/observations

[metalworker0]

Don't know how far the return pipe goes into the tank .. it would have to have a full tank to run by my guessing.

plus i don't know what the van has fitted .

catcar. info

http://www.catcar.info/ford/?lang=en&l= ... 91cD09RjAz

shows the pumps in the parts list but does not point out in the diagrams what is what

note : the pumps are in the fuel line diagrams not the tank diagrams .. so assume its an external pump no labeling on the diagrams of pumps ... although they are there in the parts list

see if you can make sense of this .. i cant

he must have done a mix and match from different vans

impossible to then guess what has gone on .

SO NOW, YOU'LL HAVE TO GO OVER THE WHOLE SYSTEM AND MAKE SURE YOUR FUEL IS BEING FILTERED BEFORE IT REACHES THE HIGH PRESSURE PUMP

all the best.mark

[Altransit]

As said, it would probably work, until the return pipe was above the diesel level, and the fuel wouldn't have been filtered