Idle Surging 89 TPI
Thread Starter
Burning Brakes
Joined: Mar 2004
Posts: 923
Likes: 4
From: Austin Tx
Idle Surging 89 TPI
Usually hang out in the C3 section, but I've been having trouble lately with one of my other cars, an 89 IROC Z with 350 TPI. I know except for alum heads, its basically the same motor as an 89 vette. Anyway I'm having an issue with the idle going up and down 1-200 rpm at idle, but only after it is warmed up, however it doesn't do it all the time. Most prevalent after driving then you come to a stoplight, or I get back home, put in park, then it starts doing it in a rythmic pattern. If you rev it a few times, it seems to "clear out" and the idle stabilizes. Here is what I've done so far. Cleaned IAC, and throttle body. Reset timing from 12 deg to 6 deg. Neither helped. Also notice a distinct odor, after shutting the car down, like a sour fuel smell, or something??
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
[QUOTE=AGENT 86;1573386323]You may also want to OHM test your injectors, cold then hot, then post your numbers.[/QUOTE
Your car should have the Multec injectors the same as vettes..These injectors are known to have problems and should be one of the first things checked when you have an idle problem..WW
Your car should have the Multec injectors the same as vettes..These injectors are known to have problems and should be one of the first things checked when you have an idle problem..WW
Le Mans Master
Joined: Feb 1999
Posts: 6,470
Likes: 2
From: levittown pa. usa Even a bad day with my `Vette, is better than a good day at work
St. Jude Donor '10
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Pro
Joined: Oct 2009
Posts: 679
Likes: 0
From: vero beach florida
9 times out of 10, surging is a vacuum leak.
Injectors would be all the time, it is amazing how many people pick on Multitecs, almost as much as the opti.
Could also be a bad TPS, have seen them cause all kinds of problems.
A bad FPR would also cause this.
Injectors should be be between 13-17 OHM's and test while hot, I had one that tested consistently at 15 cold and then 11 hot.
Injectors would be all the time, it is amazing how many people pick on Multitecs, almost as much as the opti.
Could also be a bad TPS, have seen them cause all kinds of problems.
A bad FPR would also cause this.
Injectors should be be between 13-17 OHM's and test while hot, I had one that tested consistently at 15 cold and then 11 hot.
Last edited by surfer92; Apr 11, 2010 at 11:29 PM.
