I recent restored an 81, 280 ZX Turbo. It ran fine, and then started having trouble starting. Found that the Power Transister was bad. We assumed that the new MSD coil was to much for it, and reinstalled the old coil. The problem has returned, Check connections, all ignition components check out fine. I replaced the fuel pump, and general performance improved. I had the car out tonight, and it died coming up to a stop. Had trouble starting. Can not seem to locate problem. Help needed.

 

check injectors
air flow meter
TPS
then rip out some more hair

Rusty Datsun x 3

 

the 81 turbo has an ignition system that was only used that one year and only on the turbo, (I am working on one with the same problem now I am waiting for it to act up so I can test it.) next time It dies or wont start check for spark. If you have spark it most likely isn't ignition. if there is no spark check if the injectors are firing if not you need a crank angle sensor next to the front of the crank. it sends a sig. to ecm. which uses it to ajust timing, injector pulse and more. if it dosent work the injectors wont fire the fuel pump wont run and the igniton wont fire. if that is ok the next moste likely is the ingitor next to the coil. it also could be the ecm but not likely the crank angle sensor sends to the ecm then the ecm sends to the ignitor. ignitor part number is 22441-V0800 list 152.44
the crank angle sensor 23731-V0801 402.23 ouch. as soon as this one acts up and I can test I will let you know.
onefstz

 

This is exactly the same problem I'm having. The crank angle sensor checks out, as does the ecm. The injector were all cleaned and tested. Temp sensors all fine. The car died 3 week ago and would notstart at all. Found the Power Transistor was gone. I assumed the new high output MSD coil was the reason, so put original back in. I have a feeling, the transistor is going again, but what is causing this to happen???? Any ideas?

 

I didn't see in your post wen you replaced the coil did you replace the transistor?
onefstz

 

Yes, I went back to the original coil. Also,I had the car in the shop, when they found the Power Transistor, and at that time they said they had check all the other components out. However, I pulled the Air Flow Meter out last night, and found the resistance values were way out. They should read as linear when gate is in motion,. Resistances were really bad. I have since ordered an Air Flow meter. Hopefully this corrects my problem. If you haven't check yours, might be a good idea.