Surging Idle.... What's the cause?
Thread Starter
Team Owner
Joined: Aug 2000
Posts: 40,156
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From: San Pedro CA
Surging Idle.... What's the cause?
On the famous Mr Mojo Delaware Crab Cruise, my 92 had the opportunity to idle for a little while here and there....
But it was having a tendency to surge a bit... it would be idling nice at about 800 or so, then jump to 950 and then back down... not constantly, but occationally.
And the A/C didn't make much of a difference.
I am trying to remember... doesn't that mean Opti is beginning to go bad?? or is that something else.
The O2's are due for replacement... and the opti is getting close...
But it was having a tendency to surge a bit... it would be idling nice at about 800 or so, then jump to 950 and then back down... not constantly, but occationally.
And the A/C didn't make much of a difference.
I am trying to remember... doesn't that mean Opti is beginning to go bad?? or is that something else.
The O2's are due for replacement... and the opti is getting close...
Instructor
Joined: Jan 2002
Posts: 245
Likes: 0
From: Newport News VA
Re: Surging Idle.... What's the cause? (bogus)
I had that same problem in my 94. Thing would idle find around 600 then jump to 900 or 1,500. Drove me crazy. Dealership said it was the Power Control Module. Once this module got to normal operating temp it would idle badly. $450 fixed it however, it also revealed that my opti was now bad ! ($1,500). Hope this is not your problem also !! :cry
Melting Slicks
Joined: May 2001
Posts: 2,143
Likes: 7
From: San Diego CA
Re: Surging Idle.... What's the cause? (bogus)
That was the first indication that my opti was going bad. Replaced opti, idle smoothed right out!
9T4YY1 - I'll bet you didn't need a new PCM. I hope you saved the old one it would be good for a spare.
9T4YY1 - I'll bet you didn't need a new PCM. I hope you saved the old one it would be good for a spare.
Thread Starter
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Re: Surging Idle.... What's the cause? (John Row)
I am not seriously worried about WHAT it is... I can fix whatever is wrong.
Tonite, I am going to test some codes, and get out my VOM and run it on the MAP and see what I find.
I was just looking for some areas to narrow the search down to... I would like to think that if the PCM was junk, I would see a code.
I was going to replace the MAP anyhow... 113k miles, eh? might as well. Besides, it could also explain the rather crappy startup in cold weather. It gets all poppy and spitty...
THANKS!!!!!!!!!! :cheers: :thumbs:
[Modified by bogus, 3:01 PM 6/24/2003]
Tonite, I am going to test some codes, and get out my VOM and run it on the MAP and see what I find.
I was just looking for some areas to narrow the search down to... I would like to think that if the PCM was junk, I would see a code.
I was going to replace the MAP anyhow... 113k miles, eh? might as well. Besides, it could also explain the rather crappy startup in cold weather. It gets all poppy and spitty...
THANKS!!!!!!!!!! :cheers: :thumbs:
[Modified by bogus, 3:01 PM 6/24/2003]
Team Owner
Joined: Sep 2001
Posts: 62,160
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: Surging Idle.... What's the cause? (bogus)
I had a hunting idle when it gets hot, turned out to be a bad plug wire and a vacuum line with a crack in it.
Racer
Joined: Nov 2002
Posts: 300
Likes: 0
From: Perth WA
Re: Surging Idle.... What's the cause? (vader86)
I have the same problem (89). I read my manual and it has a list of about 20 things that could cause the problem. It is just a matter of eliminating each one. I have started with the cheaper ones first. It is now better but still surges a bit.
Good luck.
Good luck.
Burning Brakes
Joined: Aug 2000
Posts: 1,052
Likes: 1
From: traveling nowhere fast, FL
Re: Surging Idle.... What's the cause? (timallard)
Cleaned my throttle body and the surging was 50% gone, new opti eliminated it. Got 99k out of the opti. Idles like a caprice now.
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Burning Brakes
Joined: May 2002
Posts: 831
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From: Iowa City IA
Re: Surging Idle.... What's the cause? (bogus)
i would bet money that it is the opti--mine does that same thing. and when the engine gets hot or i have been driving it a while, it will stutter while accelerating from a low rpm.
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From: Punta Gorda, FL
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Re: Surging Idle.... What's the cause? (kawboy5792)
mine did the same, $20 fix. I put in a new TPS. The TPS cured the wacky idle problem. Its worth a shot, better than spending the $$ guessing its the opti.
