C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

89 runs rough when cold, fine when warm

Thread Tools
 
Search this Thread
 
Old Jun 19, 2015 | 04:00 AM
  #1  
cv67's Avatar
cv67
Thread Starter
Team Owner
15 Year Member
 
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Default 89 runs rough when cold, fine when warm

No visible codes......

Guess is the CTS, anyone else?
Reply
Old Jun 19, 2015 | 07:27 AM
  #2  
ex-x-fire's Avatar
ex-x-fire
Melting Slicks
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2009
Posts: 2,237
Likes: 286
Default

It could have dirty injectors, a cold engine needs more fuel. So if the injectors are dirty, they may be allowing the engine to run lean. The ecm might not set a code for this.
Reply
Old Jun 19, 2015 | 10:19 AM
  #3  
volkswagens-for-life's Avatar
volkswagens-for-life
Melting Slicks
 
Joined: Nov 2013
Posts: 2,264
Likes: 3
From: Orchard Park NY
Default

At what temp does the car start to run properly? There is closed loop and open loop mapping which ties into what ex-x-fire said.
Reply
Old Jun 19, 2015 | 12:15 PM
  #4  
cv67's Avatar
cv67
Thread Starter
Team Owner
15 Year Member
 
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Default

Dont know the exact temp looking at the car tomorrow
Its a TA but TPI same as a Vette
It sat for a yr in storage and started doing it when he pulled it out

When my 89 Vettes injectors went bad it was slightly rough cold and real bad hot (closed loop).

Dont want to have to pull a TPI apart in this heat, have no garage now.
To pay someone it would take over a grand, hoping for a quick fix, its a pretty clean ride.
Reply
Old Jun 19, 2015 | 12:23 PM
  #5  
crowz's Avatar
crowz
Melting Slicks
25 Year Member
 
Joined: Jun 1999
Posts: 2,931
Likes: 127
From: Ashland Alabama
Default

Usually on the trans am I had the rough cold smooth warm was the coolant temp sensor being bad.

The computer and the gauge have separate sensors.
Reply

Get notified of new replies

To 89 runs rough when cold, fine when warm





All times are GMT -4. The time now is 06:40 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


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