Calling Crasher-I'm desperate now!

[bobfrankish]

OK, after yesterday I can add 2 things. My theory that the engine did not cut out when revved is not correct. I wedged the throttle butterfly with a cable tie so that the engine maintained about 1500 rpm and it still cut out after about 40 mins running. After it had cut, I removed the king lead from the distributor, held it about 5 mm from ground and cranked the engine, loads of spark. Whilst engine was cranking, I put the lead back into the distributor and engine started and ran, very lumpy, would not rev, cut out again. Left the car for about 30 mins, started up again fine. I am going to change the fuel pump and pressure regulator I think. After all, they are 27 years old and that would eliminate the fuel delivery side of things.

[Crasher]

That reminds me of something, run the engine with the pressure regulator vacuum hose off, I have known the diaphragm fail and allow fuel to flood into the engine via the vacuum hose.

[bobfrankish]

Was worth a try I guess. No difference I'm afraid, vacuum inlet to pressure reg. is bone dry, no fuel getting past diaphragm. Might buy pressure gauge and tee into fuel supply to rail, see if there's a pressure drop before it cuts out?

[Crasher]

Isn't there a port on the rail?

[bobfrankish]

Possibly. It's a long time since I had that rail off so can't remember to be truthful. I was just thinking that £22 from ebay for a tester kit might be better than about£70 and some time and grief to change the fuel pump for nothing. What do you think?

[mickeybo]

when i do a check in a tank fuel pump it is always a amps draw check. the pressure system on your vehicle vacuum off 3 bar regulated vac on 2,5 vac holding after 10 minutes 2 bar minimum after 10 minutes check holding pressure

[bobfrankish]

Thanks Mickeybo. This is my basic thinking... If an engine stops and is not seized, it is either fuel or spark related. Done plenty on the spark side- coil, sensors, dizzy, dizzy cap, relays etc. Done nothing on the fuel side. I am looking for something that could work OK to start with, then fail when it gets hot maybe. Could possibly be fuel pump. I speak to lots of mechanics, one told me last week his garage had an Audi A3 with a similar fault, kept cutting out mainly on idle, turned out to be fuel pump. Just ordered a pressure test kit, we'll see where that takes me.