C4 General Discussion General C4 Corvette Discussion not covered in Tech

Idle issue

Thread Tools
 
Search this Thread
 
Old Jun 27, 2020 | 09:39 AM
  #1  
Polizei45's Avatar
Polizei45
Thread Starter
Advanced
All Eyes On Me
Liked
 
Joined: Aug 2015
Posts: 68
Likes: 4
From: Lake View New York
Default Idle issue

My 1996 LT4 runs great with the AC off. When I turn the AC on at idle it's a rough idle at a stoplight. It doesn't stall. Is this just the load from the AC pump turning on?
Reply
Old Jun 27, 2020 | 10:36 AM
  #2  
Nowhere Man's Avatar
Nowhere Man
Team Owner
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2003
Posts: 54,059
Likes: 9,394
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
Default

sounds like you have underlying issues.
Reply
Old Jun 28, 2020 | 06:57 AM
  #3  
grandspt's Avatar
grandspt
Drifting
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2004
Posts: 1,353
Likes: 291
From: MA
Default

Originally Posted by Polizei45
My 1996 LT4 runs great with the AC off. When I turn the AC on at idle it's a rough idle at a stoplight. It doesn't stall. Is this just the load from the AC pump turning on?
If your engine idles fine without the AC on I would make sure that your AC compressor is not binding up (it probably is not otherwise your serpentine belt would probably be squealing with the AC on when revving the engine).
If you have a lot of miles you may want to pull off your throttle body and remove the IAC (you can sneak ithe IAC out without removing the throttle body from the intake manifold but it may be harder to get to the two mounting screws, and harder to clean the throttle body IAC passages).
Clean the pintle on the IAC and also the IAC passages in the throttle body.
They probably are gummed up. Make sure you use a cleaner safe for the IAC so you don't ruin it. Get a new O ring for the IAC before reinstalling it and also get a new throttle body to intake manifold gasket, otherwise you will have more idle issues.
I have used Mass Air Flow sensor safe cleaner sprays for this type of job in the past and had good luck.
Reply
Old Jun 28, 2020 | 07:47 AM
  #4  
Polizei45's Avatar
Polizei45
Thread Starter
Advanced
All Eyes On Me
Liked
 
Joined: Aug 2015
Posts: 68
Likes: 4
From: Lake View New York
Default

Thanks grandspt. It only has 28,000 on it. I'll check the compressor.
Reply

Get notified of new replies

To Idle issue





All times are GMT -4. The time now is 08:53 PM.

story-0
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-1
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-2
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-3
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-4
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-5
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-6
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-7
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-8
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-9
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE