hey we've got a 93 lt1 ecu connected to our 96 engine with all 93 electrical components except for the distributor. when the vehicle starts it runs fine for about 2 minutes then starts missing real bad. we have already been through 2 ICM's and 2 coils (coils were replaced to see if anything was affected). the vehicle is also running on speed density not MAF.

we were told that it could be grounds that were bad, so we checked all grounds and grounded our ICM straight to the block itself. still started missing after only a few minutes. i dont think it could be the heat because the engine didnt even get warm before it started missing.

we are on our 3rd ICM and dont want to keep replacing these because they are $100+ a piece.

any thoughts? suggestions? im also looking for a pinout of the four connectors going to the 93 ecu.