740 poor running and stalling

[Beadybc]

I have now replaced the spark plugs, distributor cap and HT leads and it is still not running properly. If the engine is warm/hot it will only fire if I pump the accelerator whilst turning the key, otherwise the starter motor just turns over endlessly. Once it starts it dies instantly unless I keep the revs up with the throttle.

Could these possibly be symptoms of a faulty Fuel Pressure Accumulator? = https://www.skandix.de/en/spare-part...upply/1029873/

It's the only part of the under-car fuel supply system that hasn't been replaced yet. I can't test fuel pressure but would these symptoms not indicate that there is no fuel pressure at start-up? Also now that the fuel pump is whining I am noticing that it is not producing one tone of noise, every second or so there is a quick jump in pitch as it is working harder for less than a second.

[panda529e699]

Just a thought, if the injector 'O' Rings were replaced.

[Laird Scooby]

Originally Posted by panda529e699

Just a thought, if the injector 'O' Rings were replaced.

I think they were Andrew but it might be worth athought if not.

As you might guess from my instructions on checking the cam timing, i'm trying to take the OP back to basics so we can run through a certain method that has worked for me to try and get it running as it should. It does sound as if one injector is leaking though so excess fuel rather than air might be the problem on that one - alternatively it may be pulling excess air from around a fault injector "O" ring and causing the misfire resulting in unburned fuel.

[Beadybc]

Originally Posted by panda529e699

Just a thought, if the injector 'O' Rings were replaced.

I did go to get some of those however when I sprayed WD40 into where the seals sit to see if the revs increased, there was no change. On the other hand now that I think of it the other day I did think that I saw some liquid sitting in with injector 1, don't recall looking at the others.