Hello at all!

I have a 1980 Pontiac Firebird Formula with 305cui LG4 "H" engine, Rochester E4ME carburetor, o2-sensor, air pump and c4-system.

The gas mileage is a little bit high. 16 miles per gallon equals. The spark plugs are very soot-black, the exhaust gases smells at a rich fuel mixture.



When i check the trouble code, it flashes 5 and 1, therefore it is 51. The GM-manuals says PROM-failure.




So good i can do, i have controled all the sensors, wires and solenoids, have controled the PROM seat.

My Problem is, i don't know, is the ECM and the PROM the right for my car. The ECM seems to be refurbished in the past.

They are lists with numbers, wich ECM and PROM are in wich cars?


My Numbers are:

The PROM is an delco 1337 AL, the ECM an 77-4670

I hope, you can help me to eliminate the failure.

Bye, Alex