i just installed a hypertech thermomaster chip in my 87 IROC.
it now has less power,the check engine light is on, it idles at 1500RPM and the car wont comunicate with my scan tool. I took the chip out put the stock one back and the car runs perfect. the car has a 160 stat , a 185 fan switch, adjustable fuel pressure regulator set at 50 psi, headers no cat and a borla 3" exhaust. any advice??

 

Whoa!! 50psi!!!! I think your looking for the TPI board, not TBI. It's all good though. Hypertech chips are no good to begin with, and I would try to return it for a full refund if I were you. However, my guess would be that you have the wrong chip for your engine. If you are set on using a hypertech chip, then check the number on the chip, call hypertech, and make sure it is the one for your car, i.e. correct year, engine size, manual or automatic, etc. Best of luck

 

yes i screwed up it is a TPI . I bought the chip from Summit so im sure they will take it back. What should i do for a chip instead. Is JET or Superchips any better? How much improvemant is a chip really worth anyway?

 

The general concensus is that aftermarket chips to include tbi and tpi suck. Period. Use the $150 or so on other mods instead, or put the money towards chip burning equipment. I had almost the same exact mods as you did when I installed the thermomaster. I didn't feel anything-if I knew better, I would say it slowed me down. To find out more info on after market chips, try a search. Much has been discussed on them.

 

i bought a superchip for 200.00$, and noticed absolutely no difference, I think it actually slow me down. It made my car miss and run like crap. But i was able to get my money back.