bob-95-firebird

My son purchased a 95 firebird formula with a 5.7L engine LT1 I think that someone has make some mods to the PCM because the speedometer is off by 10 miles a hour. We changed the timing chain, new spark plug, wires, new rear end, and new Trans. Now the car runs poorly (rich) and idle ruff. So we went out and purchased an ALDA 16 pin OBD2 connector and down loaded both TSS($EE ver) and EFI Live V4 (vehicle file lt1-8051_mo_a). I believe the connection between the pc and the OBD2 is working I have used hyper terminal and can see data coming down the line. But both software can not link up with the PCM. EFI Live Is ok with Max232 echo but the Chatter will the link up. TSS (DataMaster) will not show any data. I have also download a program that reads the PCM code and save it as a file and it comes back with an error message stating that it can not read the data. Do I have a bad PCM? I pulled the CPM and checked the serve no. 16188051 which is the correct one for this car. How can I tell if the PMC is bad? Or is there sometime else I should check?

Thanks for your help.
Bob

todddchi

iTrader: (3)

If you have a bad ECM the car would not run.

THe speedo being off sounds more like a gear install w/o programming.

Find the axle code (GUX, where X is a number) and tell us how fast it is actually going at 2000 rpm.

2.73's were stock in autos, 3.23's option.
3.42's in all manuals.

Sounds like it might have been a 2.73 car that got 3.23's put in.