George Posted June 10, 2011 Report Share Posted June 10, 2011 I have some engine managment questions. I have a '94 Cutlass convertible 3.4 with an auto trans. I would like to swap in a 5- speed manual trans from a '92 GP SE 3.4 donor car. Does anyone know if swapping the '92 engine harness and computer will work in the '94 and keep the check engine light from coming on. I did a search and found mostly 3.1 related info, also found out about the firewall plate for the clutch pedal. Will I still need to install an additional clutch pedal switch? I assume this trans is the 284, is this correct? Any info and help is much appeciated. Quote Link to comment Share on other sites More sharing options...
Psych0matt Posted June 10, 2011 Report Share Posted June 10, 2011 the trans will be a 284. why do you want the engine/harness? just swap in the tranny. That would be easiest IMO. Or even if you swap the engine, leave the harness, it will work just fine IIRC Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted June 10, 2011 Report Share Posted June 10, 2011 i'd swap the the underhood harness as well... that way you would be able to just plug/play the 91-93 PCM in and use a factory PROM, since there were no manual trans W's from 94-up. it's POSSIBLE to run a manual trans with the 94-95 PCM and there are even provisions in the code specifically for it, but i can't guarantee how well it would work without a custom tune. Quote Link to comment Share on other sites More sharing options...
Psych0matt Posted June 10, 2011 Report Share Posted June 10, 2011 ahh, I forgot about the whole auto/manual computer thing. My bad! Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted June 10, 2011 Report Share Posted June 10, 2011 not the computer itself that's the problem, just the PROM. the PROM from the 94-95 can be tuned to allow for a manual trans, but i really couldn't guarantee it working well unless you had someone local that could tweak it to running like a factory job. also: to use the 91-93 PCM you would need to hook a MAP sensor up to any constant vacuum source since the 94-95 motors never used one. Quote Link to comment Share on other sites More sharing options...
gpchris Posted June 12, 2011 Report Share Posted June 12, 2011 My GREEN gp is still running obd 1.5 No check engine lights or anything. I have the shifter position sensor (forget what its called) set in drive. It seems to be running perfect and getting 34 MPG at 70mph. Everything seems to be working perfect. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted June 12, 2011 Report Share Posted June 12, 2011 absolutely perfect drivability? no odd surging or idle issues? also, Chris, the 93-95 3100 PCMs are no longer "untunable", in case you hadn't heard. Quote Link to comment Share on other sites More sharing options...
gpchris Posted June 12, 2011 Report Share Posted June 12, 2011 absolutely perfect drivability? no odd surging or idle issues? also, Chris, the 93-95 3100 PCMs are no longer "untunable", in case you hadn't heard. No way! How long have I been away? Jesus. It did surge in park and neutral, but it runs smooth in drive. When the speedo sees speed the rpms raise but they don't drop back down until it reaches exactly 0mph. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted June 12, 2011 Report Share Posted June 12, 2011 i remember you mentioning surging, i didn't know forcing a "drive" combination with the PRNDL switches fixed it, i thought you did that for the rev limiter. Quote Link to comment Share on other sites More sharing options...
gpchris Posted June 12, 2011 Report Share Posted June 12, 2011 Your right I did have surging. It drove me crazy but it doesn't do it anymore. I'm 99% sure it was because I put it in drive. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted June 12, 2011 Report Share Posted June 12, 2011 well, if it works consistently, can't complain. i ASSUME the same would be true of the 94-95 LQ1 stuff. if not, at least it's something that can be changed easily. Quote Link to comment Share on other sites More sharing options...
George Posted June 15, 2011 Author Report Share Posted June 15, 2011 Thanks guy's, There was a thread about using a switch on the clutch pedal to to make the ecm think the torque converter was locked up. Would that be needed with the '92 ecm? My mecanical skills are pretty good, however, my ecm communication to car comprehension is pretty much non-existant. So I'm kind of hosed in that area. Quote Link to comment Share on other sites More sharing options...
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