Hello! I’ve been running into a weird issue with my new to me 89 camaro. Normally it will slightly hesitate however, after about 15 to 20 minutes, it loses half its power and the check engine light comes on, and it will backfire out of the exhaust. It has a lot of new parts/sensors like spark plugs, plug wires, IAC, ignition coil and ignition module. I ran the codes and got codes 10, 35, 44, 55. I am thinking it may be an ECM due to all of these popping up at once and one of them being a code for ECM issues.
I checked the timing and base timing was at 0° however when I hooked up the ECM, it advanced way out of the scale to the point I could not see it from the top.
This is my first order car so I apologize for my lack of knowledge, but any advice is greatly appreciated!