A friend of my cousin's 1999 Tahoe After replacing coil, ign module and pcm, what else would cause no spark? Before I got to it, he changed the coil, module, crankshaft position sensor and fuel pump. I verified all those items were working and tried a salvage yard PCM from a 98 Tahoe.
I wasn't aware of the need to match up the numbers on the PCMs. But with that PCM, I got spark and the truck would start then die as if it was just running on the fuel pump prime. I felt pretty certain that the proper PCM would solve the problem so I got another salvaged PCM with the proper number and tried it. No dice. No spark again. I took that one back and got another PCM and got the same result. No spark. I think I am missing something simple but am at a loss.
Friday, June 8th, 2012 AT 2:30 PM