I've recently done a single turbo conversion but I now seem to be experiencing problems with the idle.

It did it before, but seemed to sort itself out and has just randomly started doing it again.

Basically, the idle will rise to 2500rpm and there is nothing I can do to change it. However, every now and then it will drop and the idle hunts between 800 and 1500rpm

I've checked the inlet manifold and elbow for leaks on the gaskets, which I cannot find. I've also checked the vacuum hoses and again no joy. Finally, I cleaned up and lubricated the throttle body and idle control valve, which helped slightly.

Could it be that my idle control valve is knackered? The car is still driveable, but its just somewhat annoying (and loud).

Thanks

Dan

 

If the ISC is hanging open, it will cause a hunt idle situation as you describe. By the sounds of it though, you have already had the ISC off and cleaned it out, correct? If so, then you need to ohm check the solenoid to see if it has gone bad. There is a section in the FSM that covers this. I believe it has an ohm range stated there that will establish if it is within operating specs.

 

^^ The ohm range is 10.7 to 12.3. See page F-83 of the FSM