I have a volvo 240 turbo b21ft. it will not idle correctly. if i adjust the idle and mixture to where it will actually idle, the idle hangs. blip it up to 3000rpm and it will stay there for almost 15 seconds. and if we adjust the mixture and the idle to where it wont hang, it misses horribly.

we have swapped out the idle air control valve, all of the vacuum hoses, even swapped out the ECU. im open to any and all ideas. PLEASE HELP!

 

Have you cleaned your throttle body. My 740 was giving me idle problems and I took the TB off and cleaned it and that fixed the problem. It is pretty simple. There instructions on IPD's website. On the 740 their is one bolt that is a tight fit but it is doable.

 

Hows the frequency valve on your car? Are the wires to it good? Is the hose on it fresh?

 

Update? I will add that if you ever need KJet parts let me know.