So about a month or 2 back I got a 92 Firebird with the 3.1L v6 and I have loved it, but on the way home code 32 popped up and ive been chasing it since. Initially I noticed no change in performance with or without the code/check-engine-light on. One day she started surging rpms when coming to stop. This issue has since stopped after a new TPS and MAP sensor. My next attempts to solve the code 32 involved replacing the EGR, ECM, and a temp sensor. The code persists BUT is more well defined and predictable now. The only thing I can think of now is perhaps a new thermostat and chasing vacuum and electrical.

Current symptoms:

• Code activates after driving 55+ mph for a few minutes then slowing below 55 mph by brake or by coasting.
• Runs rich (can smell gas fumes from the exhaust specially after code activates)
• Average temp reading is ~180F and will climb to 240F when idling then drops back to ~180F (stays at ~180F when moving)

 

Ok so since this post was made the issue has changed. I found the source of the code, damaged wire on the connector to my EGR. code is gone now but surging idle has returned. Its started with surging when coming to a stop in drive whether i had exceeded 55 at some point or not (the 55mph part seems important as it has behaved differently depending) It will drop just below 500rpm then surge up to 1k and try to pull the vehicle forward.

I cleaned the IAC valve and reset it in the ECM and it helped. Replaced a piece of vacuum tubing and suddenly it would idle smooth at 550-600rpm in drive if i had exceeded 55 at somepoint but would still surge if i hadnt exceeded 55. However i just got back from the store and the drive there she shut off twice at red lights despite having exceeded 55, attempted to shut off several times on the way back and shut off the second i pulled in at home. I've got a new IAC valve coming atm and im also planning on replacing distributor cap, rotor, and ICM later.

 

Have you checked the brake booster? Had similar issues with cutting out or surging at stoplights lately with my car. It wasn't so evident on a cold start. I assume because it runs rich in open loop and can compensate for a vacuum leak from the booster internals. However, the more the car ran the worse it would run (or not) when coming to a stop.

 

I have not checked the booster yet but I'll add it to the list. However after re-positioning my TPS and finding a second bolt for it (those m4.5 bolts are a pain) coupled with a new O2 sensor, pressure test for the pump/regulator, and bleeding out air from the fuel system. (and rigging my EGR's disintegrating connector) The problem of surging idle at stop is now gone and she idles at around 550-700 in drive. The code 32 pops up intermittently and with it the gas smell but i havent isolated that yet. Since she is working atm I am content to leave her be for the moment and just enjoy driving her again.

 

Had the same problem w/ surging and intermittent shut off. Chased the sensors. Finally installed new GM Delco ICM. Make sure to have plenty of dielectric grease. To date my problems have been rectified. The car runs great. Now on to next project.