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

Stumbles, surges and erratic idle

Thread Tools
 
Search this Thread
 
Old 08-21-2002, 07:34 PM
  #1  
MEBVette
Heel & Toe
Thread Starter
 
MEBVette's Avatar
 
Member Since: May 2002
Location: Mantua NJ
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Default Stumbles, surges and erratic idle

I have a 93 Auto and have had stalling and hesitation problems for some time now. The problems seemed to clear up after changing both the fuel filter and fuel pump sock. Now it's back and worse.

Here is the problem. At idle, the RPM's now vary from 750 to about 1100, with the AC off. When in gear the RPMs will approach 1000. I get occasional stalls when stopped for a light. When driving I get either a hesitation during normal acceleration or an outright stall. The car runs great at 70 mph (1800 RPMs) but if I get in it to accerate I will get a momentary hesitation (not a downshift). I have stumbling upon acceleration.

I have replaced the plugs and wires, the MAP,the filters, the IAC and the fuel pump (IAC and FP by the dealed). The dealer reports the TPS and O2 sensors as good. I have no codes set in the computer and have tried a new PCM and saw no change. The dealer said that the everything looks great but that the computer is losing its learned program now and then.


Any suggestions? I am at a loss and don't know where to go (unless to another dealer).
Old 08-21-2002, 07:43 PM
  #2  
carter200
Safety Car
 
carter200's Avatar
 
Member Since: Apr 2000
Location: Texas, GOOD OLE USA
Posts: 4,643
Received 0 Likes on 0 Posts

Default Re: Stumbles, surges and erratic idle (MEBVette)

Sounds like new ECM time, IMHO :seeya
Old 08-21-2002, 07:48 PM
  #3  
MEBVette
Heel & Toe
Thread Starter
 
MEBVette's Avatar
 
Member Since: May 2002
Location: Mantua NJ
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Stumbles, surges and erratic idle (carter200)

Been tried. Dealer put and new PCM in and ran car for an hour. Had the same problems. I am starting to think there is a bad ground clearing the computer but have no idea where to look.
Old 08-21-2002, 09:02 PM
  #4  
CoolVette86
Race Director
 
CoolVette86's Avatar
 
Member Since: Sep 2000
Location: Partying with the Cowboys cheerleaders in Mt. Olive, New Jersey
Posts: 12,182
Likes: 0
Received 1 Like on 1 Post

Default Re: Stumbles, surges and erratic idle (MEBVette)

Been tried. Dealer put and new PCM in and ran car for an hour. Had the same problems. I am starting to think there is a bad ground clearing the computer but have no idea where to look.
Did ya check the thin red wire going from the positive battery post to the ECM? I know my '86 has one... it's used to power the ECM, maybe yours is loose or broken?

Get notified of new replies

To Stumbles, surges and erratic idle




Quick Reply: Stumbles, surges and erratic idle



All times are GMT -4. The time now is 02:45 AM.