1989 IROC TPI, manual, 305.

I've been having all sorts of fun issues with this car. There is low mileage on the engine - 60k miles +/-. Primarily, i'd be underway and there'd be a sudden power drop with check-engine codes indicating MAF and ECM problems. The ECM and MAF are now new, but problem not solved.

With this power drop, it could generally be corrected by keeping the ECM module down at floor level and oriented in a way to prevent undue pressure on the wiring into the ECM. The car was maybe operating at about 85% in this scenario. Of late, I was confirming the timing was correct, it was (thankfully i'm not that useless). In checking the wiring with the car idoling I noted that two wires could be pulled at the cap with little impact on engine performance, which seems to point to two cylinders not operating properly.

I am still getting an ECM/ MAF code, I believe, but battery recently changed, so I need to see what codes are popping once it cycles through.

I guess, generally, my question is whether anyone has had similar problems and knows of a potential solution, or at least a checklist run-down of what I should be looking at.

Thanks.

 

Since you have replaced the ECM and the MAF with a continuing code, and think you have a wiring sensitivity at the ECM, I would start with a careful look at the wiring at both ends. One of the most frequent wiring issues in electronic controller systems is at the connectors with a bad pin or two. The more times that a connector is removed and reinstalled, the more wear occurs on the pins. First, look at the pins to be sure that none of them have backed out of position in the connector body. Next, the best way is to buy a few pins sets that match the connector pins. Take a mating pin and check each socket or female pin on the connector. You need to look for all the sockets to have a significant drag on the pins. If you find pins that are very low drag or slightly loose, you need to replace them. There are tools (picks) so that you can use to remove the pins from the connector bodies.
If your MAF is reading wrong, fuel mixture will likely be inaccurate.