1992 Gmc Sierra-tuning Options!

Steve92GMC · July 21, 2007

Hey everyone! Need some help finding a tuner or chip for a 1992 GMC Sierra that my father and I are working on. The truck started out stock with a 5.7L and auto tranny. Early this year, we swapped motors out in favor of a 350 c.i., 290 HP GM crate motor (Pre-85 if memory serves correct). For those who have done research, the motor we got IS NOT a direct replacement engine for this year truck. Heads are slightly different amidst other things. With some mix and matching of engine parts from different years, we were able to get it running. We installed a set of JBA shorty headers, modified the y-pipe, essentially making it a "true" 2.5" dual exhaust with Magnaflow mufflers and no cat. On top we weren't able to use the stock intake manifold, so we opted for a Holley Pro-Jection manifold and 670CFM TB. We also got rid of the stock fan, and put in a pair of electric fans that are tied to a remote/adjustable temperature switch. The truck runs okay, but I won't lie to you and say it runs without problems (reading this far, you should see why). Obviously, the ECM is not understanding something...a couple of things.

This leads me to my first question, is there a reputable tuner out there that offers chips that would suit our setup? This isn't a daily driver, but rather a project we took on. Can anybody recommend someone's services? What about a better ignition (more spark)...can anyone vouch for the quality of a specific one? Looked at MSDs coil, but don't know if its worth it or not.

Please help!

svensk · July 21, 2007

Hey everyone! Need some help finding a tuner or chip for a 1992 GMC Sierra that my father and I are working on. The truck started out stock with a 5.7L and auto tranny. Early this year, we swapped motors out in favor of a 350 c.i., 290 HP GM crate motor (Pre-85 if memory serves correct). For those who have done research, the motor we got IS NOT a direct replacement engine for this year truck. Heads are slightly different amidst other things. With some mix and matching of engine parts from different years, we were able to get it running. We installed a set of JBA shorty headers, modified the y-pipe, essentially making it a "true" 2.5" dual exhaust with Magnaflow mufflers and no cat. On top we weren't able to use the stock intake manifold, so we opted for a Holley Pro-Jection manifold and 670CFM TB. We also got rid of the stock fan, and put in a pair of electric fans that are tied to a remote/adjustable temperature switch. The truck runs okay, but I won't lie to you and say it runs without problems (reading this far, you should see why). Obviously, the ECM is not understanding something...a couple of things.

This leads me to my first question, is there a reputable tuner out there that offers chips that would suit our setup? This isn't a daily driver, but rather a project we took on. Can anybody recommend someone's services? What about a better ignition (more spark)...can anyone vouch for the quality of a specific one? Looked at MSDs coil, but don't know if its worth it or not.

Please help!

Take it to a dyno

Steve92GMC · July 21, 2007

Well at this point I need more than a dyno. I can get time on one, but then I am back to square one...trying to find a chip, or someone who can tune the truck, then make a chip. Here locally, I can't seem to find anyone who specializes in older GM trucks.

jason2006 · July 22, 2007

cfm-tech.com tunetyme.net tbichips.com

Steve92GMC · July 22, 2007

Thanks for the information. Ran a code check on the truck and it appears we have a bad ESC module and MAP sensor. Also, checked the TPS sensor and had to recalibrate it because the voltage was out of range. We are going to replace the ESC mod., knock sensor, and MAP sensor this week. We also have a 3" single exhaust, high-flow cat., and y-pipe on the way. I'll check out the websites you gave me to see what they can do for us.