My friend just bought a 87 iroc 355.AFR heads Accel/lingerfelter superram.vig converter.headers etc etc.The car was built in 1999 and been in storage since.the owner stated it would die after 20 mins of running after CEL came on.and the it would be hard to restart etc.bogs realy bad when the cel comes on.It has a custom chip(unknow)I wanted to know if the tpi ecms have some sort of limp home mode they go into.It runs great when its not acting up(beat a 2010 ss rolling 3 times before the guy gave up)The main problem is I don't know cam specs etc to try and get a new chip.I think it running rich and was wondering if it runs rich to long if the computer can't control it back to 14.7 if it puts in into limp mode.its seems like if you shut it off and get it restarted it runs good again??? Thanks

 

Yes they have a limp mode and it is very rich, worse with over sized injectors.

When the CEL comes on, pull the codes and see what it doesn't like.

It could be anything, codes and data logs are few of the only ways into the ECM's mind.

I would not get a new chip, you have gold in that car's chip. A new chip would be like putting a rag dress and dirt on a beauty queen.

 

I know before it had a code 33.but I don't think hes checked lately,my scanner won't comunicate with it because of the chip I think.Hes set the tp sensor and it has a adjustable MAF from Granitialy but I thought he should wait to get a air/fuel ratio gauge before messing with the calibration on it. Thanks for the info

 

im having this same problem...car runs rich and hot....i also have a custom chip..scanner wont read anything it turns off when its times to turn the key during the scan.....my 86iroc was originally a 5.0 it got replaced with a remanufactored 5.7....24 lbs. injectors.....am i able to put my stock chip inplace of my custom chip to see if runs the scan...please help me guys...tired of my car running bad...