P38 V8 2000rpm on startup

chrish22 · Nov 21, 2009

Hi

I've just finished putting the motor back together after a head gasket change and now I have a problem, when the engine starts it revs at 1500rpm and then slowly climbs and stays at 2000rpm within 30 seconds.

Now I popped a spring out of the throttle linkage and aren't to sure I've got it back correctly although theres nothing obvious throttle position seems closed! Any pointerrs to a picture would be good on this one!

The climb in revs almost seems sensor driven but are any sensors likely to fail having just been taken off n put back on again?

Thanks in advance

Chris

wills · Nov 21, 2009

Don't know the V8 im afraid but could it have anything to do with the idle air control valve/stepper motor?? Im sure ive read about cases in the past where they hasn't been put back together quite right and caused problems

-Wills

nathan5346 · Nov 21, 2009

chrish22 said:
Hi

I've just finished putting the motor back together after a head gasket change and now I have a problem, when the engine starts it revs at 1500rpm and then slowly climbs and stays at 2000rpm within 30 seconds.

Now I popped a spring out of the throttle linkage and aren't to sure I've got it back correctly although theres nothing obvious throttle position seems closed! Any pointerrs to a picture would be good on this one!

The climb in revs almost seems sensor driven but are any sensors likely to fail having just been taken off n put back on again?

Thanks in advance

Chris

i had similar problem after a coil and battery change, i took battery off fer a minute and it was fine dunno if it reset summat, check both the throttle and c/c cable are seated correctly

eightinavee · Nov 21, 2009

Make sure there is freeplay on the throttle cable and that the arm goes to the fully closed postion.If it still revs too high then you need to have the stored closed throttle voltage reset - after checking its smooth operation in live data.The stored voltage needs to be from about .48v up to .7v.

chrish22 · Nov 22, 2009

Ok looks like the garage are going to have to reset that voltage thing.

Have checked all the physical stuff and left battery disconnected and still no joy.

Interestingly though if I disconnect the idle control valve the car still gets to 2000rpm but it takes like 10 minutes or so instead of 30 seconds - this makes me think it is computers / sensors type of issue.

I hate doing all this work at home n then having to take it to a garage to finish off

Thanks for all your suggestions.

P38 V8 2000rpm on startup

chrish22

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wills

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nathan5346

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eightinavee

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chrish22

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