C4 General Discussion General C4 Corvette Discussion not covered in Tech

L98 cold start idle problem

Thread Tools
 
Search this Thread
 
Old Sep 29, 2012 | 08:58 AM
  #1  
mickey5's Avatar
mickey5
Thread Starter
Drifting
15 Year Member
All Eyes On Me
Liked
Loved
 
Joined: Mar 2011
Posts: 1,693
Likes: 144
From: on Barnegat Bay Joisey
Default L98 cold start idle problem

just changed the injectors in my L98 ZF 6 speed. The new problem (didn't do it before) is that for the first few minutes after a cold start it will not idle. Take your foot off the gas and the idle immediately drops to 300-400 RPM and stalls. After this initial period it will idle fine at 800 RPM until you shut it off and let it cool down. Then its the same thing over again. Is there an adjustment I'm missing?
Reply
Old Sep 29, 2012 | 09:48 AM
  #2  
AirForceOne!'s Avatar
AirForceOne!
Drifting
 
Joined: Jul 2012
Posts: 1,796
Likes: 14
From: Nampa Idaho
Default

Have you checked the throttle position sensor?
Reply
Old Sep 29, 2012 | 10:23 AM
  #3  
joe paco's Avatar
joe paco
Burning Brakes
 
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
Default

the mem-cal, I think it is, has to re-learn the signals, volts, resistance, whatever, one possibility. you can unhook TPS to get a reaction. if the idle air contol was unhooked, may need to be reset. book says to depress throttle slightly with key off, start engine and let it run that way for 5 seconds, shut off for 10 seconds.

the problem with my solutions are that engine idles ok when hot.

if it is sensor related it should set a code.
Reply
Old Sep 29, 2012 | 02:47 PM
  #4  
mickey5's Avatar
mickey5
Thread Starter
Drifting
15 Year Member
All Eyes On Me
Liked
Loved
 
Joined: Mar 2011
Posts: 1,693
Likes: 144
From: on Barnegat Bay Joisey
Default

if it is sensor related it should set a code.[/QUOTE]

If it sets a code will the "check engine" light come on?
Reply
Old Sep 30, 2012 | 08:41 AM
  #5  
joe paco's Avatar
joe paco
Burning Brakes
 
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
Default

Originally Posted by mickey5
if it is sensor related it should set a code.
If it sets a code will the "check engine" light come on?[/QUOTE]

normally, yes. nothing is "always" on a C4. but unplugging a sensor, example, will normally set a code, if one wanted to test it. if it is intermittent, code will set and light could be off.

there are a dozen or more connections and vac lines that were touched when changing injectors. I would remain aware that one might be loose, whatever.

check for codes.
Reply
Old Sep 30, 2012 | 11:49 AM
  #6  
mickey5's Avatar
mickey5
Thread Starter
Drifting
15 Year Member
All Eyes On Me
Liked
Loved
 
Joined: Mar 2011
Posts: 1,693
Likes: 144
From: on Barnegat Bay Joisey
Default

Thanks for the suggestions. Now I have a place to start.
Reply

Get notified of new replies

To L98 cold start idle problem





All times are GMT -4. The time now is 04:02 PM.

story-0
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-1
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-2
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-3
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-4
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-5
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-6
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-7
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-8
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-9
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