Coupe 2.0 16v Cold Start Issues

[lagz33]

Hi guys, have posted about this prob before.
Problem has returned and I have no clue what to do.
Pre-warning I dont know a HUGE amount about engines but am quite capable.

Ok so, the problem:
When starting from cold, engine turns over then dies after starting, I can do this 4 /5 times and the engine will stay on but needs time to rev cleanly otherwise it stutters and dies again.

HOWEVER

If i unplug my differential pressure regualtor (DPR) it will start first time and run fine up until 5-10 minutes of driving, it will then start stuttering and hesitating on acceleration. A couple of times it got to the point where my foot was on the floor and it would not rev apart from bucking forward every couple of seconds (the bucking was uniform like vrr vrr vrr vrr vrr) till I struggled to the kerb and unplugged the DPR, bit of a pain considering I was in the middle of London at the time.


When this first started happening I bought a metering head (including the DPR) and a new Idle Control Valve, after that it seemed to dissapear, would start every time and have a ***** load of power, wheel spinning in second and all sorts.

So now I am back to square one, have tried the old idle control valve but no joy.

Any ideas?
I have spoken to a mate that works for AA, he mentioned cold start valve and other things to do with temps etc.

Thanks in advance guys, I know one of you will diagnose it perfectly for me


PS. K-Jetronics Fuel System

[GazzaG60]

heres a few bits. im not sure on your engine exactly so here goes.

1. lambda probe. if it has one replace it.
2. water temp switch. there should be one for the ecu. think its in the side of the head above the box. if not it may be in a water pipe and its blue. replace it.
3. IDLE valve. doubt that but worth checking the continuity on the idle switch on the throttle body. also try unplugging it.
4. there is a process to set the idle if there is a screw on the throttle body. its warm up, unplug the temp switch. rev to 3k. adjust idle on screw to about 900rpm. rev to 3k. plug in the temp swith again.
5. try unplugging the ISV. only do this with the engine off and no key in the ignition at all. the circuit is not fused and unplugging while powered can blow ecu and throw into clicky relay reset.