High Idle (TB Problem) Advice please
Thread Starter
Drifting
Joined: Aug 2002
Posts: 1,857
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From: Yakima WA
High Idle (TB Problem) Advice please
OK, I think my Throttle Body is wearing out. The spring doesn't always retract fully and reseat, thus causing my idle to run at around 1k. I can hit the gas and it will sometimes go back into place. Question is, does it sound like the spring mechanism is wearing out and should I replace the TB with a 52MM Eldebrock from Mid-America? Will a 52MM give any better performance? Thanks, in advance for the help.
Pro
Joined: Oct 2002
Posts: 638
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From: tampa fl
Re: High Idle (TB Problem) Advice please (dbwade36)
the factory TB's are pretty good quality. I would just pull it off and rebuild it..ya know....clean it out. Then reset the idle/TPS Voltage using the GM shop manual. My vette has a high idle b/c the chip is messed up right now. I just disconnected the IAC connector when it was in Diagnostic mode after 30 Secs which causes the IAC to push all the way out.... then i set the idle screw to 600RPM idle in gear....which gives me a 800 N/P idle. runs decent. if i did'nt do this i would be buying a tranny soon. it idled at 1,500-1,600 when it wanted, 1K in gear....all over the place. i went through all the vacum lines, like 3 IAC motors, 2 TPS sensors...nothing. Dam thing liked 1,600RPM to much. I need the PROM re-burned. so start by cleaning yours out well.
-Jason 89 Auto Coupe
LOW 13's
-Jason 89 Auto Coupe
LOW 13's
Instructor
Joined: Apr 2002
Posts: 178
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From: Maineville OH
Re: High Idle (Fast_vette89)
Mine does the same thing, even after a removal and cleaning. What I do is take some WD40 and open the throttle all the way, then hose down the coil spring on the outside. That seems to fix it, temporarily at least. Maybe the spring is getting corroded and binding against itself when the plates try to close. I re-lube every couple of weeks. I am thinking about trying some white lithium grease, but haven't gotten around to it yet.
Le Mans Master
Joined: Jun 1999
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From: Chino Valley AZ
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Currently Corvette-less
Re: High Idle (TB Problem) Advice please (dbwade36)
The throttle butterfly shafts tend to wear in the body pivot areas. This is especially true on the side of the TB where the radially wound return spring is located due to the constant spring pressure. This wouldn't be a problem except that when the shaft drops in the pivot area, the butterflys which are already precision fit into the throttle bore starts to drag.
A short term fix is to lubricate the shaft where it penetrates the throttle body, but eventually this even fails to correct the problem. Out of all the cheap fixes I have read about, the most economical seems to be to just buy a new or used Throttle Body. I have read where a person has taken the TB to a clock smith and had them install brass bushings in the TB housing. There is no doubt that this correct the problem and will provide for an extra smooth throttle operation ~ my only concern with this fix is the removal of the butterflys from the shaft, re-alignment of the butterflys upon re-install, and proper peening of the screws to ensure they don't come out during operation.
~ Purp :seeya
A short term fix is to lubricate the shaft where it penetrates the throttle body, but eventually this even fails to correct the problem. Out of all the cheap fixes I have read about, the most economical seems to be to just buy a new or used Throttle Body. I have read where a person has taken the TB to a clock smith and had them install brass bushings in the TB housing. There is no doubt that this correct the problem and will provide for an extra smooth throttle operation ~ my only concern with this fix is the removal of the butterflys from the shaft, re-alignment of the butterflys upon re-install, and proper peening of the screws to ensure they don't come out during operation.
~ Purp :seeya
