Just finished a head swap on my LS
The car wouldn’t start!!! car is a 91 LS 5spd
after trying a few different things, swaping a obd1 distributor (T42), which also needed a leg grinded to fit next to the solenoid. Confirm getting spark & fuel, check base timing and the white mark is a degree off when cams are lined up (OEM pr3 cam gears). But its not enough to be a full tooth off.
-I am using a p28 ecu with a skunk2 chip(4.8k vtec) and I know its not a great tune, was only going to be temp. untill I get dyno tuning. I tested the ecu in a 93 GSR, it started the car, idled ok, drove fine, vtec was fully engaged by 5k, which is earler then his stock 1.7 crossover.
-Using a jumper harness I found off Cregslist it was used and did not come with instructions. After searching the net I was able to find a company that sold a obd0->obd1 jumper that matched the single 12 pin connector wire colors. I used 7 of the 12 wires, 4 went to oxygen sensor, 2 went to vtec pressure, 1 for solenoid, there are 5 left, 2 are used to pull codes by jumping, 2 go to a ITR manifold, and 1 for a knock sensor.
ok so even if I screwed up all the wiring, or I found and used the wrong instructions, these instructions & harness have 2 red power wires and 3 black ground wires, instructions don’t specify which goes where. But thats not the point. None of those sensors / wires would prevent the car from starting or even idle or drive correct?
after 3 days of scratching my head and swapping distributors, checking spark, ect, ect… I plugged my old stock LS ecu back into my wireing harness. car fired right up, idle is nice 750, revs up fine, needs a valve adjustment but is still quieter than I ever got my solid lifer LS, that thing alwase ticked.
ok so if the p28 is good (I will re-test), and the engine is all together fine, what is the problem? bad jumper harness? Does the p28 need to see a obd1 distributor? Was I supposed to do anything to my fuel injector resistor block? I’m using my stock LS fuel rail & injectors,
Thanks for everyting guys!! will keep updating what I figure out.
ps. I baselined my car on a dyno at school befor the swap, 3rd gear 122hp / 117ft-lb all stock exceped for a open air box and zip-tye’s. after everything is strait I will dyno again.