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1983 280ZX Turbo
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Discussion Starter · #1 · (Edited)
This happened to me a few years ago, and @zmanofwashington gave me a tip that solved a problem that had been bugging me for more than a year after engine work and down time. It came in handy again today and I thought I should share it.

EDIT: @zmanofwashington gave more info in Post #3. This applies to 81-82-83 ZX turbos. Thanks for the correction (below) .

The symptom was the car was missing, and would not rev above 3000-4000 RPM. Occasionally it would rev up to 4K or more, but most of the time it simply would not rev and just had no acceleration when I gave it gas. This made the car essentially undrivable. The fix worked, and I had no problem for a couple of years.

However, over the past couple of months I didn't drive the car and its battery dropped pretty low. When I drove it today after charging it, it once again refused to rev and had all the symptoms of the previous problem. I did the same fix and the car now runs perfectly!

OK - to re-cap, the first time around when I fired it up and drove it, the car would NOT rev, and I tried everything I could think of - plugs, wires, checked injectors, made sure the injectors were firing. Then @zmanofwashington clued me in.

EDIT: I learned the 1981-83 ZX turbos had a new style ECU for Nissan that could get "confused," and that it was possible to do what is essentially a "hard reset" to it.

I disconnected the battery, then removed the driver's side kick panel to access the ECU. I disconnected all three wiring harnesses from the ECU. Then I simply let it sit for a couple of minutes.

Then I reconnected the wiring harnesses, replaced the kick panel and re-connected the battery. and the car now runs PERFECTLY. As far as I can tell, this simply let the ECU discharge its memory and start over.

This is a pretty model-specific fix for the 1981 through 1983 280ZX Turbos, but I thought it worth sharing.

EDIT: My thanks to @zmanofwashington for the corrections (see post #3) which I added to my post.
 

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Nice (y)

gotta love the Zman.... he is such a wealth of Z knowledge and seems to really really know the ins and outs of these cars. I typicall save all his posts here, because I always learn something new with each one, whatever the issue is.
great stuff.

this is a pretty cool trick. I will try it on my 83 turbo swap (everything seems to be from an 83 or a very late 82.
but I got other problem children to deal with.... injector not firing, injectors leaking, bad fuel hose, etc.... once all that gets squared away, I will try the reset trick.

Thanks!

Bon
 
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Pilgrim, a couple of minor corrections on your post. All 3 models of the 280 zx turbo ecu's (81-83) had a micro processor in them that would learn your driving habits good or bad. If you drove it hard then it would give you max G force every time, if you drove it easy like a light footed granny then it would forget how to give you max G force when you wanted it. This was of course in the verrrry early days for a micro processor and it had limited potential. One of the gliches in the early processor was that it could use just about anything to build bad memory, a miss in the ignition signal, dirty connections in the EFI circuitry, or even a low output on the alternator or even a weak battery. This can cause a multitude of potential running issues for the engine. To clear the memory circuit you have to unplug all 3 plug ins for the ECU OR disconnect the battery whichever one you choose. You don't have to do both and you should leave one of them unplugged for at least 15 minutes. To the best of my knowledge the turbo ZX was the first production vehicle to use a micro processor in the automotive field. Z man of Washington
 
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