how can i tell if my computer is shot?

at first glance , you'd say "well duh, the car would run like crap, andnot have much power". well my problem is that i think something is holding the engine back, and it's been this way ever since putting it in. i bought a new harness from street and performance, and it had the obd1 port all set for me. after putting in a bogus f body #, it couldn't establish a connection. this was with auto x-ray. i had a friend try his program with his laptop, same thing, couldn;t establish a connection...

this would be a lot easier to troubleshoot if my f body drivetrain was in an f body. lol. it's in an 89 gmc sierra tho. basicly i have the lt1 (stroked), t56, and a few other goodies as well. had brian at PCM do the first tune, but i know it needs another tune, a real dyno tune.

my questions are this. anything particular i should look for since i can;t make a connection at all with any computers? it runs, but i think it's in open loop or whatever the computer switches to when it senses something is wrong. runs real rich, seems like it should be snappier than it is.

i'd like to be able to check the status of the 02 sensors before i go broke buying new ones :p

who is the best dyno tuner for the lt1's in CT? (looking other than j&m, not too happy with the service)

You need to figure out whats keeping you from being able to datalogg first. From the sounds of it you probally have a bad sensor or something.

OH and btw.. I've seen harnesses from them and howel have pinouts crossed up.. so simple mistakes aren't beyond them.

You need to figure out whats keeping you from being able to datalogg first. From the sounds of it you probally have a bad sensor or something.

OH and btw.. I've seen harnesses from them and howel have pinouts crossed up.. so simple mistakes aren't beyond them.


:D you're right bout that, i was popping fuses big time when i first installed it. after 6 hours of tracking ohms, we found that it was the passenger side 02 that was wired backwards. :rolleyes:

i'd bet a ton that it's the 02's that are crap. i've never replaced them since i've owned the truck. i'm just about positive that the pins on the data link are correct. if i remember right, they matched my book diagrams, as well as some online diagrams i found. i do remember that the old harness that the truck came with was wired different for some reason. but that whole harness was shot, it had to be replaced. according to all my diagrams, i think it's correct. i'll double check when i get a chance.

i hate to be a "replacement mechanic", but do you think that is the route to take? do you think it is my internals in the motor that are doing it? (the motor was supposedly built for a solid lift , massive cam. it was a drag motor that the previous owner couldn't afford, so i bought, and had the engine builder put in a hydro cam a tad larger than the hot cam. 1.6 rockers,motor is stroked, 58mm bbk, intake and heads completely ported and polished, etc.) the motor should easily make 450 hp from what i'm told . i dunno. running 30lb ford injectors. STOCK fpr. ( i was told that it should be fine, still not sure on that one) could all that be throwing the computer for a loop?