L98 Idle Problem
Thread Starter
8th Gear
Joined: Oct 2011
Posts: 8
Likes: 0
L98 Idle Problem
Been looking through the FSM, but can't find what I need for this 91 6-speed coupe. Hope someone can help.
When I come to a stop sign, the idle stays up about 2k. If I quickly "stab" the throttle, idle drops back down to normal. Almost as if the carb linkage is hanging up on the fast idle cam. Course, this ain't no carb, Vern.
Am I missing a spring? Throttle Position Sensor? Idle Air Controller?
Thanks!
When I come to a stop sign, the idle stays up about 2k. If I quickly "stab" the throttle, idle drops back down to normal. Almost as if the carb linkage is hanging up on the fast idle cam. Course, this ain't no carb, Vern.
Am I missing a spring? Throttle Position Sensor? Idle Air Controller?
Thanks!
Racer
Joined: Oct 2007
Posts: 478
Likes: 1
On mine I had to add a spring but it was no where near 2000rpm. Mine was around 1100 and a light spring was all that was required to bring the throttle back on the stop. Your throttle body may need a cleaning and a little lubrication applied. Maybe a spring too.
Safety Car
Joined: Aug 2009
Posts: 3,745
Likes: 275
From: Melbourne, Victoria, Australia
Been looking through the FSM, but can't find what I need for this 91 6-speed coupe. Hope someone can help.
When I come to a stop sign, the idle stays up about 2k. If I quickly "stab" the throttle, idle drops back down to normal. Almost as if the carb linkage is hanging up on the fast idle cam. Course, this ain't no carb, Vern.
Am I missing a spring? Throttle Position Sensor? Idle Air Controller?
Thanks!
When I come to a stop sign, the idle stays up about 2k. If I quickly "stab" the throttle, idle drops back down to normal. Almost as if the carb linkage is hanging up on the fast idle cam. Course, this ain't no carb, Vern.
Am I missing a spring? Throttle Position Sensor? Idle Air Controller?
Thanks!
Check your cruise control cable adjustment?
I have had a similar thing happen some years ago, turned out the cruise control cable was preventing the throttle from returning all the way. The IAC will try to compensate, best open the throttle mid way and very slowly bring it back it and check if it stops correctly.
The accelerator cable or cruise control cable could be sticking, holding the throttle slightly open.
If all else looks good check your IAC valve works and tps voltage or do a base idle adjustment as per your shop manual.
Good luck
Thread Starter
8th Gear
Joined: Oct 2011
Posts: 8
Likes: 0
Turns out there is a tremendous amount of freeplay (slop) in the throttle cable. I may need a new cable, but it's almost impossible to get to the pedal if you are not a contortionist.
Took the easy way out and added a spring for now and idle comes back to 900-1100. Interesting that there is a stud on the throttle body cam and a hole 4" away that looks tailor-made for a spring (and where I put it) but there is no spring from factory from what I call tell from FSM.
Thanks for the replies. Great forum here!
Took the easy way out and added a spring for now and idle comes back to 900-1100. Interesting that there is a stud on the throttle body cam and a hole 4" away that looks tailor-made for a spring (and where I put it) but there is no spring from factory from what I call tell from FSM.
Thanks for the replies. Great forum here!
