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83zxt no spark, new power transistor.


captken

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hello,

Kenny here.

 

I have a 83zxt. I installed the Jim Wolf tech package for the 280zxt.

 

I had the car running smoothly, but had no power when driving.

I found it was running on 4 cylinders, the other two cylinders not fireing at all.

Found fault with 2 of the 6 dropping resistors supplied with the Jim Wolf package.

I have replaced all of the resistors, not the Jim Wolf supplied, but within specs.

After installing the resistors and reinstalling the harness, I got no spark.

I had a warranty for the power transistor from Advance Auto Parts and picked up a new one today. Installed it still no spark.

The car started right up and was running before I pulled the harness. Now I have no spark.

 

As I understand it, when you turn the key, the dizzy spins and sends a signal to the EFI relay which in turns sends a signal to the ecu, which in turn sends a gating signal to the power transistor to tell the coil what to do.

 

My problem is finding out what to check to troubleshoot this problem

 

I know the problem is minor, because the car was running before I took the wiring harness out to replace the dropping resistors.

 

I need to back trace from the power transistor to the battery.

 

thanks in advance for your help,

kenny.

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disconnected something and didn't reconnect after the work. I'd recheck everything you did. After that just start eliminating problems. Don't neglect rechecking the battery and associated cables. most places load test for free. battery cables with corrosion can cause problems as zx sensitive to voltage.

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Yes, the car was running after the jwt upgrade. [it has to have the 10w-6.8ohm resistor installed, the 81 car had the resistors already]

Problem I believe was a friend who reinstalled the wiring harness snagged the resistor bundle, pulling it thru the firewall, lost 2 wires to resistors.

So all I did was pull the harness and reinstall 6 new resistors. I elimated the plug for the ACC valve, and shortened the wires to the Cobra maf, so it would look better under the hood.

Thats all I did.

 

Checks I performed:

 

I pulled the dizzy and rotated the shaft and heard the injectors fireing, and the fuel pump cycling on and off as I spun the shaft.

 

Question:

Does anyone know how many times per rotation the injectors are suppose to fire? I think the dizzy is working okay.

 

I turned the ignition on and heard the fuel pump frun or 5 seconds, then turn off, which is normal. I then tried to start the car but I could not tell positively if the fuel pump was running with the ignition in the start position. Somehow I don't think it did.

 

The fuel pump may not have been running in the start positon of the ignition switch.

 

I tried to test yellow wire to the igniter by red lead to yellow, black lead to ground, and cranked over the engine.

I probably had the vom on the wrong setting, but it measures, I believe,

.2v. And that reading was pulsing as the motor turned over. It that the test for the gated signal, it was pulsing on the yellow wire to ecu.

 

I need more information to diagnose the spark issue and what to check.

 

I pulled the harness today, and untaped the loom, searching for problems. Have found none with the wiring I did.

 

I hate to reinstall it only to have the same problem.

 

The harness for the power transistor goes into the fender thru firewall.

 

How does this harness to the power transistor tie into the ecu?

 

thanks a million in advance,

 

There is a guy who posted today on zcar today that is experiencing the same problems I am having.

 

here is the link, http://www.zcar.com/forums/read/1/2081796/2081894#msg-2081894 maybe the Zgods on both forums can help 2 people having simular problems at the same time.

kenny.

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disconnected something and didn't reconnect after the work. I'd recheck everything you did. After that just start eliminating problems. Don't neglect rechecking the battery and associated cables. most places load test for free. battery cables with corrosion can cause problems as zx sensitive to voltage.

 

New battery new cables, with proper grounds.

 

Trying to check everything out. The only thing I found unusal was the sheilding wire around the dizzy connector to harness connector pulled away from the plug. Was like that when I bought the car, did not cause any problems before.

 

I believe its something simple that I over looked,

 

what are the standard test to troubleshoot no spark?

 

How does the wire to the power transistor [goes to harness in fender well thru firewall] get to the ecu?

 

kenny.

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