Back N Black
Full Access Member
Rebuilt the engine in my 96 Tahoe, and threw a cam in it, entirely new ignition system EXCEPT for the ICM. Ran it quite a bit to set the valves. At one point it just died and would not restart. My dad was helping me at this point, and put in a call to his brother, retired mechanic. He advised to try disconnecting the ICM, letting it sit for a few minutes, and then plug it back in. Did that truck started right up. I brought my Hoe home thinking it was pretty much ready to roll, except for adjusting the timing to compensate for the cam and non-adjustable dizzy. Ran fine, ran is back and forth to the gas stations that I could get to through my neighborhood. Wasn't registered at this time. After a few weeks of doing this, it seemed to be losing power, and bogging down. The first chance I had to try driving it to work, I did. It ran fine when I cranked it. On my way to work, I noticed it bogging down on me. Even died on me a couple times. On my way home, it died completely, and I had to tow it home.
Fast-forward to yesterday, I pulled my fuel lines, turned the key, had fuel pool up on the intake. I pulled my #3 plug and checked for spark, nothing. The ignition coil is a brand new MSD, the dizzy is a brand new Summit Racing (looks like the Davis Unified Ignition dizzy), and the apparently factory ICM. Talked to one mechanic friend yesterday, and he's worked on numerous Vortec motors, and says he has never had to change one. The truck has 230k miles, and has been rebuilt before, but it definitely had the original dizzy judging by how worn the gear was. I am 98% sure that my problem lies within the ICM, and I will try and get it tested tomorrow.
Have any of you ever had to replace your ICM? How many miles did the engine have on it at the time? Thanks in advance!
Fast-forward to yesterday, I pulled my fuel lines, turned the key, had fuel pool up on the intake. I pulled my #3 plug and checked for spark, nothing. The ignition coil is a brand new MSD, the dizzy is a brand new Summit Racing (looks like the Davis Unified Ignition dizzy), and the apparently factory ICM. Talked to one mechanic friend yesterday, and he's worked on numerous Vortec motors, and says he has never had to change one. The truck has 230k miles, and has been rebuilt before, but it definitely had the original dizzy judging by how worn the gear was. I am 98% sure that my problem lies within the ICM, and I will try and get it tested tomorrow.
Have any of you ever had to replace your ICM? How many miles did the engine have on it at the time? Thanks in advance!
