96 Eclipse rs high idle

[jsevron]

Hi i have a a problem
i have a 1996 Mitsubishi Eclipse rs 5speed and i just had the engine rebuild from top to bottom. Now my problem when i started the engine for the 1st time the engine idles right at 6000rpm and the speedometer goes up on its own.

what could it be?

 

[406talon]

Check intake manifold gasket, idle screw, vacuum leaks, and post throttle body gasket. Boost leak tester could help ya out as well.

 

[jsevron]

Thanks i will check all that out this weekend.

 

[boostneverlies]

Probably one of the gaskets or seals like 406talon said. Are you getting a CEL? how about isc or tps, or not enough slack on the THROTTLE CABLE?

 

[jsevron]

No i dont have a check engine light like i said as soon as i start the car it revs up to 6000rpm and the speedometer goes up on its own and my throttle cable is fine.

 

[jsevron]

ok guys i checked all of that and my car stills idles high

 

[PlanZero]

Not trying to be a dick, but how did you check boost and biss on a 420a? You said you have an rs right? I had a similar problem on my 420a and after replacing the idle air control valve tps and new tb gasket it was fine. However, when I first pulled apart the tb all "checked out" fine. I swapped tps with one from the junkyard on a hunch and it worked. Have you been able to check if your speedometer actually works? Is it holding at one spot or just going haywire? Stick or a/t? Speed sensor?

 

[shakeandbake]

instead of a boost leak its a vacuum leak you dont supply pressure you just check for leakage. But ive never seen a 6k rpm vacuum leak. one of your sensors might not have been reinstalled right or plugged back into the right connector or something. get a vacuum gauge and hook it up to your intake manifold. That will take that one out.

 

[jsevron]

ok i'll do that tomorrow i'll keep you posted

 

[jsevron]

Ok sorry i never responded the car is still doing the same thing as soon as i start the car it revs right 6k i got no check engine light i got no air leaks

here is a youtube video this is precisely what is happening to my car

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