Buick intermittant high idle and car accelerates on its own

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Robby
Posts: 1
Joined: Thu Sep 17, 2015 11:43 am

Buick intermittant high idle and car accelerates on its own

Unread post by Robby » Thu Sep 17, 2015 12:04 pm

I'm getting these symptoms second hand for a 2002 Le sabre Limited. It will do 45-50mph on hiwy without touching accelerator. I've been told accelerator is not showing any depression when driving and butterfly no open in park. Then put in neutral rpm's come down then put back in drive and it repeats. This wasn't as bad to start then got progressively worse and now constant. When in park idle ranges up and down 1200-2000 rpm's. All these symptoms occur with the cruise and A/C on or off.

Check engine light has never lit up. No codes. All sensors have been monitored with normal readings.

Throttle body has been off and cleaned. MAF, IAC, TPS, MAP, PVC all changed. Plunnem was checked for cracks when T-body off. Ether sprayed all over engine with no change in idle and no vacuum leaks can be found.

Cranks and starts normal. Does not miss or hesitate. Any Ideas?

 

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carriedi
Posts: 2267
Joined: Wed Apr 10, 2013 12:42 pm
Location: Oregon

Re: Buick intermittant high idle and car accelerates on its

Unread post by carriedi » Thu Sep 17, 2015 3:48 pm

you need to look at your IAC counts. is it high or is it low at idle when it's idling high? Look at your fuel trims too. this will tell you if the car is running rich so the IAC opens for more air, or if the car is running lean and the computer is adding more fuel.

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