Ok the title is broad but I'm at a bit of a loss and could use another brain on this. I have a 1987 Turbo MT. I will go into detail on everything I have done to this car so if you want to skip that go to the second paragraph. I bought it from a guy that did an EGR delete and added an intercooler set up. All of it looks pretty good. When I first got it a couple years ago it was running but very rich and eventually stopped running. I ended up replacing several components (fuel pump, fuel filter, fuel injectors, FPR, spark plugs\wires, ignition coil, CAS, ECU). I replaced the ECU because the switch on it was broken and I couldn't do any diagnostics and I found one that was in better shape. The fuel injectors were upgraded to EV6 ones on an upgraded fuel rail with an FPR that has a built in pressure gauge. I got it from Godzilla race works and it is meant to run on stock ECU and fuel pump. After this work the car started and ran beautifully! I was extremely proud because it was the first time I had done this level of work on a car and it not only started and ran, but was no longer running rich and no longer blew plumes of smoke when I gave it throttle. Also, I failed to mention, I added an oil catch can as well.

6 months after this work was done and taking it on drives 1-2 times per week, I drove the car to work and stupidly left the headlights on. The battery died and I got a jump. The car started up and I was able to drive home with no issues. The next morning I started the car and let it warm up for a few minutes. It seemed fine at first, idling at 1200rpm cold then down to 7-800 rpm once warm. After a couple minutes though I noticed that it was idling really low ~4-500rpm. I backed it out of my driveway and started to go down the road. It was very low on power and very erratic when I gave it throttle (extremely jerky). I turned around an limped it home. Later I tried looking at it. It would start, run rough for 10-15 seconds and then stall. This progressed to eventually starting but dying immediately. My battery voltage gauge was reading low (~8 volts). I charged the battery and it still reads low. The car does crank though. Just out of curiosity I attached some jumpers to the car, and when that was attached the gauge read 12.5 V. I tried starting the car then but it still just stalled immediately... I've tried a few other things. I replaced the fuel injector adapters that allowed my stock harness to plug into the EV6 injectors. I cleaned my MAF (didn't help) then I replaced it with a Delphi one (nothing changed). I check all of my grounds, fuel pump primes, my fuel pressure gauge shows I have good fuel pressure... Just can't think of what else it could be. Everything started the day after I let the battery die. My gut tells me it's something electrical but I can't think of what else to check. Sorry for this long post but I wanted to be detailed.

 

My issues were the cam sensor in the distributor. I replaced the whole distributor since the connection on the bottom for the cam sensor was breaking due to age and heat. Runs like a champ now. Also sounds like the alternator/battery have issues.

Good luck.
Larry

 

Thanks Larry, I did recently replace my CAS. Maybe I'll try swapping it out again to see what happens. I have a few since they seem to be a common problem. Gonna also check my ECU codes when I get time to do it next. Given the low voltage I do suspect something may also be happening to the alternator. Gotta love chasing issues with these cars.

 

Ok so today I was able to do a few more diagnostic tests. First I connected a noid light to my fuel injector connectors to be sure the ECU was sending to the injectors. Everything passed! Next I decided to do a diagnostic on the ECU. I got 2 codes (21 & 41) 41 I expected since I have an aftermarket FPR and it doesn't have a connection for the fuel temp wiring harness. I've heard people say that this sensor is super important and others say it does nothing. What I can say is that for the past 6 months it ran fine without it, so I don't think it's the culprit. Now code 21 on the other hand is no spark detected from primary ignition coil. This is likely the cause of my issues. I read a few ancient forum posts about this and it seems like it may be as simple as replacing my ignition coil. Funny thing is is that I replaced my old one with an NGK one about 2 years ago. I always thought highly of NGK but either way I ordered a Bosch one from Rock Auto and we will see what happens when it comes in next week
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I finally got the car running smoothly again! Turned out to be the CAS as you suggested. That plus my ignition coil transistor. I first replaced the ignition coil transistor. The car would then start right up, idle for a few seconds and the the rpms would slowly drop until the car stalled. That's when I decided to go ahead and replace the CAS. Once it came in, a quick swap and presto! Car fires up and ran great... Well after the ECU did it's relearning thing. Took it for a casual 20 minute drive today and it was awesome. Thanks for the tip! I ended up getting a couple spares just in case.