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

89 idling problem hheeeelllppp!

Thread Tools
 
Search this Thread
 
Old Feb 14, 2010 | 07:12 PM
  #1  
stevie1dr's Avatar
stevie1dr
Thread Starter
Pro
10 Year Member
 
Joined: Jun 2006
Posts: 508
Likes: 1
From: Miami Florida
Default 89 idling problem hheeeelllppp!

My 89 is giving me fits. I recently made it into a 383 and even more recently installed the FIRST Injection systems complete unit consisting of bigger runners, a 835cfm throttle body, intake and plenum. My problem is that it just won't idle properly. It keeps seeking and varies between 500 and 1400 rpms, constantly going up and down and up and down etc. This creates a real problem trying to put it into gear in any direction, as it stalls if I don't feather the brake/gas pedal until I get it rolling. Once over about 1000 rpms, it runs fine. It just won't idle smoothly at a normal steady rpm. I checked for vacuum leaks and found none, and the the TPS is working ok. I'm stumped, as is my tuner. Anybody have this problem or have a cure. I'M GETTING DESPERATE!!!!

Steve
Reply
Old Feb 15, 2010 | 08:05 PM
  #2  
Paul Ruggeri's Avatar
0Paul Ruggeri
Former Vendor
 
Joined: Nov 2006
Posts: 2,482
Likes: 3
From: Carmichael ca
Default

Do you have any scan data? What's the base timing set at?
Reply
Old Feb 15, 2010 | 11:47 PM
  #3  
stevie1dr's Avatar
stevie1dr
Thread Starter
Pro
10 Year Member
 
Joined: Jun 2006
Posts: 508
Likes: 1
From: Miami Florida
Default

Paual. I don't have that data right now, but will be back on the dyno on Saturday. If it's ok with you, please send me your e-mail and phone through a pm so I can discuss this easier than typing. I do remember my last pull on the dyno Monday with the new FIRST INJECTION SYSTEM was 285 hp @ 365 torque, which really wasn't much improvement over my previous pull with the original TPI system although it was a nice even curve to about 4800 rpm's.
However, I went to the strip Saturday nite and found a nice improvement over the old system. With the stock TPI system my best 1/8 mile was 2.14 (60 ft) @ 81 mph and the et was 8.78 seconds. With the new system I did a 1.92 (60 ft) @85.7 mph and the et was 8.32 seconds. A nice improvement, but even Ken at First says I should be doing much better then that.
Hope to hear from you.

Steve
stevefischer2@bellsouth.net
Reply
Old Feb 16, 2010 | 08:41 PM
  #4  
GlennS87's Avatar
GlennS87
Drifting
25 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Apr 1999
Posts: 1,261
Likes: 6
From: Middletown New Jersey
Default

A hunting idle could be a problem with the IAC. You should reset it per factory instructions. ( I don't have the procedure with me)
Reply
Old Feb 17, 2010 | 10:54 PM
  #5  
stevie1dr's Avatar
stevie1dr
Thread Starter
Pro
10 Year Member
 
Joined: Jun 2006
Posts: 508
Likes: 1
From: Miami Florida
Default

I don't have it either. Does anyone have the correct procedure for checking and resetting the iac?

Steve
Reply

Get notified of new replies

To 89 idling problem hheeeelllppp!





All times are GMT -4. The time now is 01:04 AM.

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