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Discussion Starter · #1 ·
hello all z heads. I have had my car 10 years and my computer module keeps breaking. I think something is causing this any hep would be incredible I'm hoping to ride it this summer with the t top off
 

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1983 280ZX Turbo
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Which computer "module" are you referring to? The engine control unit under the driver's side kick panel?

And please define "breaking." What are the symptoms?
 

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Discussion Starter · #3 ·
my ecu kkeps blowing i had it changed 5 times already i dont know whats causing it, just had car check in mechanic he told me he dont do electric so i figured its the ecu again 10 years this is happening would love to drive this summer thank you AVi
 

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I don't quite understand what your car's issue is.... what do you mean your computer module keeps breaking? the ECU either works or it doesn't.
Are you saying that you swapped in 5 DIFFERENT 280zx ecu's, and they all failed? You know, these little boxes are getting harder and harder to find now days... did you use aftemarket?
if so, aftermarket ecu's tend to either not work or are not even correct for the car. also, via the FSM there is a method to test and troubleshoot your ECU with a multi-meter. have you tried cleaning the plug contacts? these often get corroded and cause the ECUs to act funny. and that also goes for ALL the other electrical contact connections in the engine bay... these get all corroded and crappy, your car will run crappy or not run at all. what are the symptoms? (as has already been asked above)

what happens when you turn the key? does the fuel pump kick on? does the engine crank? does it start and die? does it start up good and run crappy while driving? does it die in mid-drive?

last question: is your car a turbo or non-turbo? Have you done ANY modifications?

Bon
 

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if the charging system is over charging you may be getting voltages that are too high. 1st thing 1st is make sure the battery has good cables, well grounded, and the alternator is the correct one with correct wiring. Injectors come in different resistance coil windings (impedance). I don't know this for sure, but I suspect some injectors are designed to operate at full battery voltage without any resistors to limit current. The think the zx still had the voltage limiting resistor packs in series with the supply voltage to the injectors. This is where problems begin IF someone has started messing around with mods to the car. Its essential to leave all the wiring stock if you are to have any luck trying to diagnose issues. I can only think of two things that could damage a ECU if that is the problem.
Unregulated charging voltage (this should show up on the volt meter on the dash as too high a voltage).
Modifications to the EFI as in incorrect wiring mods, damaged wire harness, wrong injectors, incorrect resistor pack (if used on the model).

Lastly incorrect ECU, the ECUs come with or with out a warning sticker. No sticker is on the early models 75-77 I think, later models used a same pin connector but are not interchangeable, and the turbo models had a completely different pin connector IIRC.
 

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1983 280ZX Turbo
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I think the next thing I would do is check voltage across the battery terminals when the engine is running. I'd also rev the engine and find out if I had voltage spikes.

It does sound like something is either over-driving the ECU or there is a short in the system (pure speculation, not something I have encountered) that damages it. My money is on a charging system that's overcharging or creating excess voltage and causing the damage.
 

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one more thing, are the correct fuse links installed on the EFI power supply leads? I would think they should save the ECU from excessive current draw (enough to fry the output transistors, if that is indeed what is happening).
Perhaps you should get some close up pictures of under the hood.
 

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The fusible links are designed to protect the car like Dave M said BUT the ecu (Driving computer) is not protected against power surges in the charging system and it's not protected against hooking up a battery backwards or jumper cables backwards. I've seen these 3 items cause a lot of blown ecu's in the 83 cars. Using the correct ECU is critical on the 83 cars. It has to be an 83 ecu. A lot of the earlier comments are spot on like battery connections. What company are the replacement ecu's coming from? What color are the injectors that were installed in your zx? Z man of Washington
 
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