Removed the carburetor and installed the FI that the PO boxed up when he couldn’t get it to idle properly. So it’s running okay but has low idle when cold and some light popping on the deceleration when it warms up but not when cold. I’m going through the FI harness checking wires and using the harness diagrams on Bowlsby.net and noticed my ECM harness plug sockets doesn’t match the 74’ or the 75’ diagrams. So I removed the ECM and no numbers letters nothing on it. Is there anyway of finding out what ECM I have? The car mfg date is 3/74’. My thinking is possibly the harness wire locations may not match the ECM. Any help is appreciated Click to view attachment

It does have a 6 pole AFM and harness plug.

Your harness is a late 1974 1.8L harness. That circuit #2 in the ECU connector is found on some of the later model year cars. It adds a circuit to the TPS if I recall and I believe I recall it being documented in factory literature. Don’t recall where without research.

Thanks!