My car's always had a problem with running extremely rough in open loop. Even after countless tune ups, various sensor changes and all sorts of diagnostics on various engine systems, I have yet to find an answer to this mystery. Just for kicks I removed the ECM today and opened it up to find a Hypertech chip in there instead of the stock one . A quick comparison of part numbers on Hypertech's website revealed that the chip is a StreetRunner Chip meant for a 5.7L TPI motor with auto trans. Now my car is actually 5.0L TPI and it used to have auto trans back in the day. It's been a year since I popped in the T5. I know L98 chips will work with LB9 engines though not optimally, but how bad is the difference? Are the symptoms similar to what my car does. Oh yeah not to mention the lousy 10mpg I get around the city. New O2 sensor, CTS, IAT sensor and lord knows what else. IAC, timing and TPS are all set within acceptable parameters and gas mileage is still shot to hell, even with the terribly tall 2.73 rear end. What gives? Any ideas anyone? I would sure appreciate if u guys could throw some ideas at me . Thanks...

 

i say you should get another chip, one meant for your car..

they must be different because the chips are made for what your car has..

see if you can get a custom burnt chip from some one on the boards.

 

any idea how much it typically costs to have a custom chip burned?

 

id expect your fuel curve to look like ***, i think the 5.0s had 18# injectors compared to the 5.7s 22# injectors. Im sure there are some other computer diffs. too. Most guys on this board will tell you to just buy stuff to burn your own chips, but i personally dont have much patience to do that. Read Traxions intro to Prom burning article. Ive read it half a dozen times, but im still not convinced to start burning my own chips.

 

I'll swap you! I have one from an 86 305 tpi auto-and I need one for my 89 350 tpi. E-mail me if you're interested.