Well, Now I think I might have really done it. I repinned my ECM from a 165 to a 730 ECU. Now I can't get the ALDL to work using either my snap-on scan tool, datamaster, or RT Tuner. I have looked at the 730 wiring schematics and the ALDL connectors to verify which wires are feeding the ALDL from the ECU. I am trying to do this from memory. I know there is one white w/black strip, One Orange wire, and I believe 1 black w/ white stripe. This did work for a short period of time and now it doesn't pick up any connection. Can I or should I wire these directly from the ECU pins using new wiring directly to the ALDL and bypass the ECU? Any thoughts would be appreciated.

 

Some MAF cars have the orange data wire in pin E. The speed density has the orange wire in pin M.
Also make sure you're telling your scan tool to look for a speed density computer. If it uses the VIN number, change the 10th digit to an M for 1991 or N for 1992.