280zx distributor on a 74' 260z

[rustler753]

So it has been discussed before, but in my searches I couldn't find a solution to my particular wiring problem. Here is what is going on. 

 

Busted out the multimeter and here are my observations. See attached for the wires I'm working and my wiring setup. Black/White: 12V ignition on, voltage drops during cranking. Black/Blue: No voltage ignition on, 12V during cranking. Black/Green: No voltage on, No voltage crank. Blue: No voltage on, No Voltage crank. My understanding is that 12V should be oscillating on the (+) and (-) on the coil, but as my wife cranked the car, I had the mutlimeter on the +/- and only saw 12V constant, I didn't see it drop out. 

 

I'm not sure what to test next, it seems pretty clear the coil isn't getting power but I wired it exactly like how the Atlanta Z car club wrote. 

 

Anyone have recommendations on how to wire this thing up? 

(I have removed the transistor module)

 

This is how it used to be wired up with the old ballast resistor/dizzy (see 3rd attachment), my ballast resistor was a 3 pole unit:

 

black/white on resistor +, black/blue on resistor center, and black/green on resistor -. The white/black paired with the black/green went to coil - and the capacitor as well. The tach was on coil (+). 

Edited April 15, 2016 by rustler753

[NewZed]

 Black/White: 12V ignition on,

Black/Blue: No voltage ignition on, 12V during cranking.

 

. Blue: No voltage on, No Voltage crank. 

 

I'm not sure what to test next, it seems pretty clear the coil isn't getting power but I wired it exactly like how the Atlanta Z car club wrote. 

 

You're showing a blue wire in your drawing from the coil negative to the tach.  Is that the Blue that gets no voltage above?  If so, that would mean you have an open circuit in the coil.  The coil is bad.  With the key On and engine off, voltage should be the same on positive and negative sides of the coil.  But you need to measure it with the wire attached to the coil negative, not disconnected.  Power IS getting to the coil on the BL and BW wires.

 

Otherwise, everything looks correct in your picture  It should work like that, with a good coil.  don't forget to make sure the distributor body is well-grounded also.  That's where the current goes after it passes through the module.

[rustler753]

You're showing a blue wire in your drawing from the coil negative to the tach.  Is that the Blue that gets no voltage above?  If so, that would mean you have an open circuit in the coil.  The coil is bad.  With the key On and engine off, voltage should be the same on positive and negative sides of the coil.  But you need to measure it with the wire attached to the coil negative, not disconnected.  Power IS getting to the coil on the BL and BW wires.

 

Otherwise, everything looks correct in your picture  It should work like that, with a good coil.  don't forget to make sure the distributor body is well-grounded also.  That's where the current goes after it passes through the module.

The blue wire is from the tach which has been in several examples as the trigger that lands on the (-) side of the coil for this conversion. I did these measurements with all the wires disconnected in the 2nd attachment and used the chassis for ground reference. Should the (-) and (+) on the coil both have 12V reference to ground when everything is attached when the key on and engine off? 

 

I also have a pertronix 1.5ohm flamethrower coil but I had the same results when I tried that coil... 

[NewZed]

Yes, with no current flowing the + and the - of the coil will read the same voltage, battery voltage, to ground, with the key On.  Just measure at the terminals of the coil, with everything connected.

 

Hook it up like your picture and it should be ready to start.  

[rustler753]

Any way to check voltage coming out of coil with a spark plug? Like plug a spark plug into the coil wire and hold it near ground to see if the coil is powered just to isolate the distributor being the issue? I've never tested the coil in car with spark leaving the coil. 

[NewZed]

You can take a jumper wire from coil (-) and tap it to ground with the key On.  That will cause a spark from the center wire if it's close enough to a ground.

 

Are you trying to figure out why your engine won't start or just being very thorough?  You might just have a bad module.

[Kurbycar32]

I just went though this on my early 260z and it turned out i had a bad coil that really confused things.  The coil worked with the factory 260z distributor but pretty much failed to function with the 280zx dizzy.  I used this document and its working.  Be sure to unplug your ignition module from the passenger footwell, if you leave that in with the zx dizzy your car wont run or at least mine didnt.

 

http://forums.hybridz.org/topic/104933-1974-260z-with-e12-80-280zx-distributor-swap-wiring-with-tach-hook-up/

 

 

[rustler753]

You can take a jumper wire from coil (-) and tap it to ground with the key On.  That will cause a spark from the center wire if it's close enough to a ground.

 

Are you trying to figure out why your engine won't start or just being very thorough?  You might just have a bad module.

Trying to figure out why it wont start. I can't get spark and just going through the routine. 

[rustler753]

I just went though this on my early 260z and it turned out i had a bad coil that really confused things.  The coil worked with the factory 260z distributor but pretty much failed to function with the 280zx dizzy.  I used this document and its working.  Be sure to unplug your ignition module from the passenger footwell, if you leave that in with the zx dizzy your car wont run or at least mine didnt.

 

http://forums.hybridz.org/topic/104933-1974-260z-with-e12-80-280zx-distributor-swap-wiring-with-tach-hook-up/

I have the pertronixs flamethrower too but both didnt work, I did pull out the transistor ignition module out. That post is also what I followed in detail, but I can't seem to get it to turn 

[Kurbycar32]

Newzed touched on all the troubleshooting points but heres exactly what i would do:

 

1. disconnect the blue wire entirely and don't worry about the tach until the car runs.

2. run through the coil test procedure in your book.  I beleive my coil is close to 1.5 ohm.  I couldn't get the new dizzy to work at all with a higher resistance coil, specifically a 3.5 ohm bosch blue.  in this case a stock coil works perfectly

3. working with a known good coil with the tach and ignition module disconnected if it still doesnt work look at the ignition module on the zx dizzy.  I was unable to find a test procedure for these but do a resistance test on it.  If the circuit is wide open is definitely bad but we cant prove its good with a resistance test (that i know of).  

[rustler753]

So I may have narrowed it down. I got fed up and swapped in the 260z dizzy, put back in the ballast resistor and didnt change the coil. Bam it starts. The coil has power, so the problem is the 280zx distributor or the e12-80 igniter itself. 

[Aswad1981]

So I may have narrowed it down. I got fed up and swapped in the 260z dizzy, put back in the ballast resistor and didnt change the coil. Bam it starts. The coil has power, so the problem is the 280zx distributor or the e12-80 igniter itself.

The Zx distributor has 5 pieces that will go bad.1) pickup coil (2) magnet (3) reluctor (4)stator and (5) black box called module. Any mal function with one of those will cause a no start or a start and stop. First how is the shaft play, if that is in spec i would get a new or working module. If the no start problem continues do a visual inspection of the of the stator and reluctor by someone who knows this datsun unit. If it passes the visual then you have a bad pickup coil and or magnet. If you have to change any one of the latter it eould be best to change them both pickup coil and magnet. Took me years to accumulate that knowledge. Good luck.