Trying to figure out if I have an aftermarket ECM or is this stock. Pictured below is the ECM in the car. The memcal has ABWN 8656 on one end and 1605536 on the other end. Trying to figure out if this is causing my running issues as I have replaced every thing else on the entire car from the MAF to the Fuel pump. Yet in closed loop it runs like crap. Had a miss on a cylinder and has this "Putting" sound from the exhaust. I have literally replaced everything on this car and it still does this. So my last ditch effort was this ECM.

 

That is a remanufactured 1227165 ecm the abwn memcal is the coirrect bcc for a 87 fbody tpi 5.7L
Options:
With GW6 AXLE, REAR, 3.27 RATIO
With L98 5.7L GAS 8 CYL MFI
With MD8 AUTO 4 SPD THM 700 R4
With NA5 FEDERAL REQUIREMENTS

 

I appreciate your knowledge sir, thank you!

 

You might want to start a new thread in tpi on what all you have replaced. You might be able to start to narrow it down to a cylinder bye pulling spark plug wires doing a cylinder drop test. If that doesnt reveal anything you should do a compression check to rule out a mechanical issue.

 

I've done all that already bud. I have done leak down, compression, pulse testor, new injectors, every last freaking sensor and relay has been replaced, fuel pump, alternator, starter, intake/plenum/runner/TB gaskets, 3 different MAF's, 2 different TPS, 2 throttle bodys and IAC's to eliminate issues there, timing chain, the entire ignition system, just everything possible. Over 1900 worth of new items and this TPI STILL has the rough idle or "Putting" sound as I call it until it goes into closed loop. When it does go into closed loop it starts rough idle, trying to die, up down idle etc. I will post a thread in there and see if I can get some input. At this point I am serious considering just yanking some bolts and sliding a 383 I have in there. I really wanted to keep this stock with TPI but I'm spent.. lol