oisintarrant

Hey, would anyone know what the following symptoms would mean...

Its a 2.5L 85.5 8v engine that when cold, starts on the button (didnt start immediately before but I replaced all the vaccum hoses and pulled out the starter to clean up contacts etc)
but when you leave it sit for 5 mins or so turned off after warming it up to running temp, when you turn the ignition, the rev needle drops (fluctuates a bit) around 400rpm and conks out if you dont gently give it a small bit of gas. If I keep it alive, for about 5 seconds after, it will hunt between 500 and 1200 rpm before settling down to idle perfectly. Otherwise it drives perfectly apart from the DME shudder which is supposed to be very common.

Any help with this is greatly appreciated as its doing my nut in.

pnbell

You could check the FPR (fuel pressure regulator) it's on the top of the fuel rail near the front of the car with a vacuum line going to it...
pull the vacuum line and see if there is gas in it
with the vacuum line attached to the FPR; suck through the other end lightly to see if it holds vacuum. It should stick to your tongue if it holds vacuum *and not taste like gas!*
ha ha

Sometimes this regulator developes a small crack inside it, and allows fuel to enter the intake causing your car to run rich... on cold startup your car likes the extra fuel, but when warm it can cause the engine to stall and foul the plugs... like a choke on carbureted engine.

Just an idea..

oisintarrant

Just swapped out the FPR for a new bosch one. I cant say it made too much of a difference. Any other ideas? Thanks!

Yarf

Fuel pump check valve?
http://www.clarks-garage.com/pdf-manual/fuel-01.pdf
Leaking injectors?
http://www.clarks-garage.com/pdf-manual/fuel-17.pdf