92 LT-1 surging at idle
Thread Starter
Racer
Joined: May 2004
Posts: 263
Likes: 0
From: Oconomowoc WI
92 LT-1 surging at idle
Beautiful day in the Milwaukee area today so I decide to take a ride. My 92 LT1 A4 was running just fine as it always does, when sitting at a stop light the idle started surging- I really had to lean on the brakes to keep it from going into the intersection. It ran a little rough as I pulled away but then smoothed out. I jumped on it pretty hard on an entrance ramp and it stumbled under WOT. The next time I jumped on it she seemed OK. The surging continued at the next stop sign. I pulled all the intake stuff of when I got into the garage and when idling there the surging continued- but seemed milder. Any ideas what I am looking at here?
Thanks
Thanks
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
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
Supporting Vendor
Joined: Mar 2008
Posts: 1,762
Likes: 14
From: Cumming Ga
Beautiful day in the Milwaukee area today so I decide to take a ride. My 92 LT1 A4 was running just fine as it always does, when sitting at a stop light the idle started surging- I really had to lean on the brakes to keep it from going into the intersection. It ran a little rough as I pulled away but then smoothed out. I jumped on it pretty hard on an entrance ramp and it stumbled under WOT. The next time I jumped on it she seemed OK. The surging continued at the next stop sign. I pulled all the intake stuff of when I got into the garage and when idling there the surging continued- but seemed milder. Any ideas what I am looking at here?
Thanks
Thanks
__________________
Race Director
Joined: Aug 2006
Posts: 18,346
Likes: 1
From: D / FW
Any one got the sequence for resetting the IAC after removing or unplugging it.
Another guy in General has the same issues and I can remember most but not all.
Un plug IAC start and idle a minute then kill motor, plug back in turn key on ten seconds then off then start and run normally.
I think thats how it goes but my FSM is 400 miles away at home.
I would try to find out for sure before doing it because I'm winging it and it's not something you have to do every day.
My LT 4 is a 383 forged beast which I have only done the procedure twice on it but it sure made the beast idle better.
Another guy in General has the same issues and I can remember most but not all.
Un plug IAC start and idle a minute then kill motor, plug back in turn key on ten seconds then off then start and run normally.
I think thats how it goes but my FSM is 400 miles away at home.
I would try to find out for sure before doing it because I'm winging it and it's not something you have to do every day.
My LT 4 is a 383 forged beast which I have only done the procedure twice on it but it sure made the beast idle better.
Last edited by larry00; Apr 26, 2009 at 11:50 AM.
Team Owner
Joined: Oct 2000
Posts: 96,443
Likes: 9
From: Fort Knox, KY
Cruise-In IV Veteran
Cruise-In VI Veteran
Cruise-In VII Veteran
Cruise-In VIII Veteran
No codes, huh? I'd check the the O2 sensors, idle air control valve, throttle position sensor, EGR valve, PCV valve, manifold air pressure sensor, and the temp sensor on the water pump. ALL these jokers can cause the idle surge problem you're experiencing.
Race Director
Joined: Mar 2006
Posts: 11,628
Likes: 1
From: Sherwood, Arkansas
I don't think it would be the MAP sensor though with out a code.
