Hot start issue

[jamespi]

I have replaced the following items in my fuel injection system in the past year or two:
Thermotime sensor
CPR/WUR
Fuel Accumulator
Fuel Filter
Fuel Pump
and I have a new set of spark plugs.

I replaced the CPR/WUR earlier this year with a reconditioned one from Ed Uding, but then had to wait for a while to get the brakes rebuilt to get an MOT. I got the car on the road again at the beginning of this week and have been driving it a bit since then. From cold, it starts up fine, but it runs rough and misfires for about 10 seconds after that. Then it runs fine. Starting from hot, you have a 75% chance of it instantly dying after it fires. If it does fire up it runs rough for a few seconds as from cold. If it doesn't fire up, the only way I've found to get it to start is to do the trick where you connect the CPR/WUR electrical connector to the Cold Start Valve instead. Then you can crank the starter and twiddle the throttle to make it splutter into life, and again after a few seconds it runs fine again. If you don't do that, you can crank and crank all day long but it sounds like the engine isn't even trying to fire.

So it seems like the engine is being starved of fuel when it very first starts up. Situations where the cold start valve is open (a cold start or when the valve is forced open by swapping the plugs) enable the engine to start.

Does anyone know what it might be?

[TheOriginalMrP]

Hi James...

Replace the pickup and question mark hose in the tank, check operation of the check valve if your fuel pump hasn't got an integral one.

I had issues like this and the state of the pickup in the tank was the obvious reason...


The car would always start alright from cold but as soon as the pump had sucked up enough debris, it would bog down. I spent years thinking it was an electrical issue. .

Worth a try

[Chris Williams]

For the cost may be worth trying this: http://www.specialtauto.com/delorean-pa ... ction.html
[ATTACHMENT NOT FOUND]
Chris

[jamespi]

Thanks Chris - i have a fuel pressure guage and i did measure the pressure going into the distributor when i fitted the WUR and it seemed exactly right. I will measure it again. I need a new boot for the fuel pump anyway so maybe i should replace the whole pickup assembly. I forced a new bit of fuel hose down the inside of the question mark hose to stop it kinking, which didn't diminish the fuel pressure despite reducing the internal diameter of the hose.

I will replace those O rings next I suppose. Is it a fiddly job? I'm nervous about disturbing anything sensitive in the fuel distributor