idle surge problem
Thread Starter
Cruising
Joined: Mar 2006
Posts: 12
Likes: 0
From: Los Angeles CA
idle surge problem
Hi folks. I've got a 1994 coupe automatic, it has about 85000 miles on it. Runs well and all that, but it has an idle problem. It surges up and down, with a frequency of about 3-4 seconds, occurs in both neutral and in drive, and does this this with the foot OFF the gas pedal. Only in idle, and when the engine is at operating temperature. It goes from about 600 rpm to about 1200 rpm. When you accelerate, it drives normal.
The car is at the mechanics, but I have little faith in him right now. He changed a couple spark plugs and some wires, but it's still doing it.
Any ideas what to look for?
Check engine light does function, but it's NOT on, so no codes in the computer.
The car is at the mechanics, but I have little faith in him right now. He changed a couple spark plugs and some wires, but it's still doing it.
Any ideas what to look for?
Check engine light does function, but it's NOT on, so no codes in the computer.
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
Check for "stored" error codes:
first thing you need to do is see if you have set any error codes:
http://www.georgiasyty.com/aldl.htm
here's another link specific to GM :
http://www.troublecodes.net/GM/
first thing you need to do is see if you have set any error codes:
http://www.georgiasyty.com/aldl.htm
here's another link specific to GM :
http://www.troublecodes.net/GM/
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Sounds like a vacuum leak or a dirty IAC/TB. I would also check the voltage on the TPS. If Service Engine Soon light is on I would start there first and check codes, but more than likely vacuum.
http://forums.corvetteforum.com/show...ghlight=vaccum
http://forums.corvetteforum.com/show...ghlight=vaccum
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
Originally Posted by RRT vette
Sounds like a vacuum leak or a dirty IAC/TB. I would also check the voltage on the TPS. If Service Engine Soon light is on I would start there first and check codes, but more than likely vacuum.
http://forums.corvetteforum.com/show...ghlight=vaccum
http://forums.corvetteforum.com/show...ghlight=vaccum
. Sounds like a vacuum leak to me too!
