91 L98 problems please help
Thread Starter
2nd Gear
Joined: Jul 2009
Posts: 2
Likes: 0
From: Del Rio Texas
91 L98 problems please help
i have a 91 vette with a l98 and its idling kind of rough so i did a complete tune up, cleaned the throttle body and timed it but still kinda rough. any suggestions on that. also when i put the car in reverse or drive it sputters really bad for about a second then shuts right off but will start right back up. any suggestions will help.
Instructor
Joined: Aug 2008
Posts: 132
Likes: 3
From: Springfield Ohio
You might try removing the IAC (IAT) Motor and spraying liberal amounts of carb cleaner into the port (engine off, of course), cleaning the gunk off of the pintle (head) and re-installing.This is a common issue with all Idle Air Control.
(Cripes! Pic wouldn't load)
see
http://forums.corvetteforum.com/c4-t...-solenoid.html
for pics
(Cripes! Pic wouldn't load)
see
http://forums.corvetteforum.com/c4-t...-solenoid.html
for pics
Last edited by basselope; Jul 27, 2009 at 10:14 PM.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Dieing when put in gear makes me think IAC. Dirty causing the pintel to be slow to respond or D.O.A.
I don't know about the 91, but is your TPS voltage adjustable? Was it removed when you cleaned the TB? If so, and if it's adjustable, did you re-set it? .54 (+/-.075 I believe is the stock setting.
Other possible causes I had with my 1986 L98:
A broken MAF wire on one occasion,
On another occasion the 02 sensor died,
Still another, a vacuum leak (hose, intake manifold, TB gasket, etc.)
Yet another the ECM wouldn't take over and control the ignition timing.
Hope this helps.
Jake
West Point ROCKS!
I don't know about the 91, but is your TPS voltage adjustable? Was it removed when you cleaned the TB? If so, and if it's adjustable, did you re-set it? .54 (+/-.075 I believe is the stock setting.
Other possible causes I had with my 1986 L98:
A broken MAF wire on one occasion,
On another occasion the 02 sensor died,
Still another, a vacuum leak (hose, intake manifold, TB gasket, etc.)
Yet another the ECM wouldn't take over and control the ignition timing.
Hope this helps.
Jake
West Point ROCKS!
