888rmb 6 Posted March 26, 2008 I've put a 2.0 S16 engine from a ZX 16v in a 309 GTi and although it is running, the idle on the car is too high. When you start the car from cold it idles at 1500 rpm and then soon increases to 1900 rpm, where it remains steady there. If you squeeze the air supply hose leading to the ICV you can reduce the idle to somewhere near 1100 rpm, but you have to be careful otherwise the engine stalls. I have interogated the fault codes from the ECU and one of them is ISCV supply fault. However checking the ISCV multiplug, there is +12v to the centre pin, coming from the fuel pump relay. The other two pins on the multiplug are an earth and by jumping these earth pins to earth individually, you can make the ISCV rotate in either direction, which seems to tell me the valve is functioning correctly. As the ECU controls the idle speed, what is wrong and how to I adjust whatever to get the idle speed down to the correct value? The air supply to the ISCV comes from the air intake and then goes through the ISCV to the throttle body. Share this post Link to post Share on other sites
stuart.m 0 Posted March 26, 2008 If cutting off the air supply to the idle valve cuts the engine out, it doesnt sound like an air leak, id try to get hold of another idle valve and try it. Share this post Link to post Share on other sites
