What year is the PCM you used when you transplanted the LT1 in to your 1990? That will determine what scan software works with it.

 

94 PCM tuned by Ion. I downloaded Datamaster, now I have to scan it and post the datalog.

 

Since I can't find my cable, I am going to fix the stuff I have found. I replaced the collector gaskets and now I can hear an exhaust leak uo front. I am going to replace the header gaskets next. I think part of my problem was a brake booster about to go. It went out on me yesterday. I capped the vaccuum line to get home and it ran better and wasn't as rich.

 

Update: I scanned the car and there are no codes. I can't datalog because my laptop is having issues. I replaced the header gaskets and changed plugs. The plugs were allblack and sooty. Since the new plugs have been in the car runs perfect. Rich like an LT1, but not too rich. Could something in my ignition be weak? Could I go to a hotter plug? I am running TR55s gapped at .050. The opti is 2 years old and the coil is also. Any help is appreciated.