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Discussion Starter #1
I have a 1982 datsun 280zx N/A, there are 2 wires that come off the plug on the side of the ignition control module. One wire is blue and white and the other wire is blue with yellow. My blue with white wire is cut off so I don't know where this connects too? I have looked through the FSM and cant find that wire. My issue is the dropping tachometer once car gets warm. I have checked CHTS and also O2 sensor and both are functioning properly. Any help would be greatly appreciated
 

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When the tach drops, does the car stall? Or is it just the tach that drops out, and the car runs fine...?
 

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When the tach drops to zero after car is warmed up it stalls or I have to give it a lot of gas to keep running. When I stop at a stop light it dies but does start up again but runs very bad.
 

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Dan, I asked because this has most of the symptoms of a bad ignition module, which is mounted on the distributor right behind the radiator.

The module starts to fail when it heats up, and since it's in the air flow path from the hot radiator, failure usually happens when the engine warms up. The tach dropping to zero is one of the symptoms. Usually the engine dies completely, but running poorly might be the same kind of tipoff.

Here's how I diagnosed it in my '82 NA. I carried a thermos of icewater in the car, and when the tach dropped to zero (and the engine died) I pulled over, popped the hood, poured icewater on the module, and I could immediately start it up. At least the test is free!

I suggest trying this and see what happens. If the engine runs correctly after doing this, I think it's the module.
 

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Discussion Starter #5
Thanks a lot for the information. I am also worried about he wire from the plug on the side of the module since one of mine is cut and goes no where.
I am thinking once I find out if it is the ignition module of mounting on the wheel well away from the radiator to try to keep it cooler.
 

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i am experiencing this same kind of problem. you should heed pilgrim's advice and see if you can cool that module down. this is a common problem on NA cars after the module gets old. but the only thing i question on yours, is that cut wire... if the wires to the module are not connected, then i guess technically your car shouldn't be able to start at all. one question: when your car dies and you try to re-start it and it won't start, do you hear the fuel pump kick on? if so, you've got some other kind of issue. i may be mistaken but i believe the fuel pump and relay are tied in to the ignition module. when mine dies and i try to re-start, the pump doesn't activate... only after i mess with starting it over and over or i just let it sit a while and try it again, it will kick back on. something else you should investigate are the fuseable links and your pump relay.

and you could also try installing another module and see if it still dies. i know thats just throwing parts at it, but these are still available and you might as well have a good spare. btw, i got one from autozone for dirt cheap. that is to say its much more affordable than the factory unit from nissan- that's if they even still carry it.

Bon
 

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Discussion Starter #7
i am experiencing this same kind of problem. you should heed pilgrim's advice and see if you can cool that module down. this is a common problem on NA cars after the module gets old. but the only thing i question on yours, is that cut wire... if the wires to the module are not connected, then i guess technically your car shouldn't be able to start at all. one question: when your car dies and you try to re-start it and it won't start, do you hear the fuel pump kick on? if so, you've got some other kind of issue. i may be mistaken but i believe the fuel pump and relay are tied in to the ignition module. when mine dies and i try to re-start, the pump doesn't activate... only after i mess with starting it over and over or i just let it sit a while and try it again, it will kick back on. something else you should investigate are the fuseable links and your pump relay.

and you could also try installing another module and see if it still dies. i know thats just throwing parts at it, but these are still available and you might as well have a good spare. btw, i got one from autozone for dirt cheap. that is to say its much more affordable than the factory unit from nissan- that's if they even still carry it.

Bon
Thanks a lot for the information, I am going to try the ice trick when it dies next time and then go from there.
Thanks a lot for all the advice.
 

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Discussion Starter #8
Thanks a lot for the information, I am going to try the ice trick when it dies next time and then go from there.
Thanks a lot for all the advice.
So I tried the ice trick after it warmed and my RPM's starting dropping to 300 RPM. The car still didn't want to run. I also took off the CHTS and the car just died when it was limping at 300 RPM. The one thing I did find my TPS when at full throttle isn't getting continuity at my ECU. I am going to track that down later, at the TPS itself I get continuity.
Could this be cause these symptoms?
O2 sensor is blinking like it should at the ECU.
Also when it starts running badly smoke comes out the tailpipe.
Any other ideas would be greatly appreciated, not sure what else to check
 

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So I tried the ice trick after it warmed and my RPM's starting dropping to 300 RPM. The car still didn't want to run. I also took off the CHTS and the car just died when it was limping at 300 RPM. The one thing I did find my TPS when at full throttle isn't getting continuity at my ECU. I am going to track that down later, at the TPS itself I get continuity.
Could this be cause these symptoms?
O2 sensor is blinking like it should at the ECU.
Also when it starts running badly smoke comes out the tailpipe.
Any other ideas would be greatly appreciated, not sure what else to check
1) what color is the smoke?
2) did the engine start up fine at first and die later while you were driving it?
3) if you remove the CHTS or it is faulty, the car won't run right.
4) I'm not sure about the TPS sensor... follow the FSM to trouble shoot that
5) the engine should still start normally even if the O2 sensor is not working
6) is the fuel pump kicking on after the car dies the first time and you try to restart?
7) did you get another ignition module? you should

Bon
 

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I'm thinking the test indicated that the module is not the problem, but given their tendency to fail over time, it might be worth replacing it in the near future.
 
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