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1992 3000GT VR4
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Well camera is at an angle when pic was taken
I see what your saying though
I still don't see where it's off a tooth
Looks like it
Need better pic to verify
 

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Discussion Starter · #24 ·
Hi!

Thanks for all your answers and as always - sorry for my late reply.

I´ve had the ECU capacitors changed by a professional electronics guy for about 150 bucks, yet nothing changed. I started over doing tests and found out that basically only cylinder 1 is getting spark, but not only that but it seems to get spark like every second or so, so its basically almost continuously sparking. I did not dissasemble the intake to get to the rear bank.

Guess its a problem of either the crankshaft or camshaft sensor or the ignition control module?

I´ve swapped the ignition coils, yet still only cyl 1 gets spark.

I guess I´m gonna fire up the parts cannon and replace the sensors aswell as the ICM?
 

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93 NA ATX 3000gt DOHC
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Guess its a problem of either the crankshaft or camshaft sensor or the ignition control module?
Of the 2 sensors, the camshaft sensor would be most likely problem.

I say that because if crankshaft sensor was bad it wouldn't fire any of the three coils, sounds like the one firing is the 1 & 4 cylinder coil. That coil should spark for ever revolution of crank, once for #1 cyl and once for #4 cyl, so it would seem fast when cranking.

As you may already realize crank sensor trigger plate has three evenly spaced flags, one for each coil. But ECU has no way of knowing which one is for which coil, without using the cam sensor pulse in conjunction with the crank sensor to determine which one is for 1-4, 2-5, or 3-6 cly coil. So without a working cam sensor, the ECU might only fire one or no coils at all. Also with the cam sensor not working the ECU can’t determine which cly needs fuel injector to fire, which is only done once per ever 2 revolutions of crank, so you could have arbitrary firing of injectors as well. Hope that helps you understand operation of the two sensors.
 

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Discussion Starter · #26 ·
Hi white93gt!

Thanks for the explenation. I will order me a new camshaft sensor and hope that it will solve the age-old problem already ;)

Is there a possibility, and how high would it be, that the ignition control module is defect? Wouldn´t it make similar problems/symptoms?
 

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93 NA ATX 3000gt DOHC
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Is there a possibility, and how high would it be, that the ignition control module is defect? Wouldn´t it make similar problems/symptoms?
If none of coils were firing the ignition control module (PTU) could be a suspect. But since one coil is firing, I’d find it unlikely that 2 of transistors failed and left one working.

There is a bench test for it if you’re handy with multi-meter and can wire up leads to a 1.5v flashlight type battery.
 
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