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

Rough idle

Thread Tools
 
Search this Thread
 
Old Sep 8, 2005 | 03:16 PM
  #1  
bvs3's Avatar
bvs3
Thread Starter
Intermediate
 
Joined: Sep 2003
Posts: 35
Likes: 0
From: Novi Mi
Default Rough idle

My car drives great when I'm on the gas, but if I stop at light or get stuck in traffic my oil pressure drops and the car starts to run rough. It acts like it's getting ready to stall, although it never quite has.

Once I'm able to get moving again everything is fine once more. The problem seems to be worse when the engine gets warmed up to operating temps.

Any ideas what the problem might be?
Reply
Old Sep 8, 2005 | 04:03 PM
  #2  
Mtrhd329's Avatar
Mtrhd329
Instructor
 
Joined: Jan 2005
Posts: 204
Likes: 0
Default

Im experiencing the same problem in my 87. Is it throwing any codes. One of mine was code 15 for the coolant temp sensor. unplugged it while i am waiting for a new one and it seems to be running fine. Now on to the other codes. ( 33 and 42)

Also a throttle body and IAC cleaning helped to smooth out the bucking and raised the RPMs at a stop in gear.
Reply
Old Sep 8, 2005 | 05:37 PM
  #3  
65Z01's Avatar
65Z01
Team Owner
20 Year Member
 
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Default


If there are idle speed issues, clean the TB & IAC and reset base idle and TPS.

If the roughness is a miss, connect a timing light in turn to each spark plug wire too see if the engine misses coincides with missed flashes at any of the wires.
Reply
Old Sep 8, 2005 | 05:43 PM
  #4  
darkman5001's Avatar
darkman5001
Burning Brakes
20 Year Member
 
Joined: Nov 2003
Posts: 935
Likes: 2
From: Beverly, NJ
Default

Originally Posted by 65Z01

If there are idle speed issues, clean the TB & IAC and reset base idle and TPS.


Clean trottle body and IAC, and reset base idle. This will probably solve the problem.
Reply
Old Sep 8, 2005 | 06:35 PM
  #5  
bvs3's Avatar
bvs3
Thread Starter
Intermediate
 
Joined: Sep 2003
Posts: 35
Likes: 0
From: Novi Mi
Default

Ok, great!

I'll give those things a shot. Thanks guys!
Reply
Old Sep 8, 2005 | 10:52 PM
  #6  
bmalec's Avatar
bmalec
Racer
15 Year Member
 
Joined: Aug 2004
Posts: 379
Likes: 170
From: Buffalo Grove IL
Default

Not sure what year you have, but if it's '89 through '91 or so, check the fuel injector coil resistance, the fuel injectors used those years have an issue with the injector coils shorting.

I had the same symptoms you describe, and it was the injectors.

Good luck!

Ben
Reply
Old Sep 9, 2005 | 09:55 AM
  #7  
Mtrhd329's Avatar
Mtrhd329
Instructor
 
Joined: Jan 2005
Posts: 204
Likes: 0
Default

So what would be the likely culprit in a 87 if the throttle body and IAC have been cleaned and the base idle reset?? It idles decent in P or N but in and gear it hunts and surges from 800 to 500 and sometimes dies.
Reply
Old Sep 9, 2005 | 12:43 PM
  #8  
65Z01's Avatar
65Z01
Team Owner
20 Year Member
 
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Default

Have you checked base timing?

Any vacuum leaks?
Reply

Get notified of new replies

To Rough idle

Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

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

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo




All times are GMT -4. The time now is 05:37 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