Weird idle problem....

[92dsmgst]

Ok i bought myself a 1995 talon TSi and it had a problem once it was warm it would idle very high (4200 rpms!) I got around to replacing the TPS and the IAC and it drastically helped, now i can get it to idle at about 800 rpms when its not to warm, but after driving for more than 20 mins it gradually rises to about 2500 rpms. I clean my MAF, MDP/MAP sensor, spark plugs and wires, thermostat, throttle body is clean spotlessly. No vacuum leaks, compression checked for head gasket leak. SOME ONE PLEASE HELP!!! I AM GOING OUT OF MY MIND!!! DSM GODS TO MY RESCUE

 

[garrek11]

Check your BISS or even your timing.

 

[92dsmgst]

biss is set right, other then it leaks boost is that a problem? on a leak down test i hear it hissing.

 

[95 'clipse RS]

i had a similar problem when my intake manifold gasket was cracked allowing too much air to get in during idle. anything on the intake side allowing excessive air to get in will raise the idle. check any possible causes, intake mani gasket, injector o-ring seals, open ports on manifold, or broken hoses. its probably a leak after the throttle body. so try to check all in between.

what do you mean it leaks boost? have you done a boost leak test, or leakdown test? a leakdown test is usually referred to as in combution chamber leakdown test. boost leak test is within everything from the compressor side of the turbo to the intake side of the head just to clarify things.

 

[92dsmgst]

sorry i ment to say a boost leak test, not a leak down. i put soapy water onn the BISS during the test and it bubbled up quite well.

 

[Dsmj89]

Then change it and re-test it for leaks.
Slowboy Racing, Inc. :: Mitsubishi :: DSM :: OEM Parts :: OEM SBR Biss Screw Kit

 

[92dsmgst]

any other ideas on why i am having this problem though? it only happens when its good and warm if that helps at all. Thought the ECT sensor could be it but it checks out good on an ohms meter.

 

[95 'clipse RS]

its sounds like you have a leak somwhere. i dont know if this could help you, but it could get worse when it gets warmer because of thermal expansion of materials. that's exactly what happened with my IM gasket when it was leaking. i also went a similar path by replacing the IAC, cleaning the TB, and replacing the injector o-ring seals with no luck until i poured a small stream of water over the IM gasket. then i heard the idle drop to normal for a second and steam come out of the exhaust. then i knew exactly where it was. the same method may be worth a try, to try to pinpoint the leak. just work over everything in the system and test them and you will find it. hope this helps

also, this may sound stupid but have you checked your throttle cable adjustment? i've seen throttle cables stick when they get hot before. just a thought though.

 

[garrek11]

or even check your readings on the tps maybe you messed up on installing it remember on the 2g's the tps has the idle control switch built in

 

[donswan]

I had a problem like that and it turned out to be the timming. Are you running a cam or crank sensor?

 

[92dsmgst]

7 bolt with a crank angle sensor