I have put in three dizzys and three ICM and Im still not getting spark from the rotor to the cap terminals. I even cut up a new cheap cap and traced the voltage, I have power from the coil to the cap, to the rotor. But for some reason the spark does not jump from the rotor to the terminals...Anybody have any suggestions,Im about to pull the rest of my hair out
Thanks

 

What year is the Z? I know the 240 - 280z's need a condensor to make the spark jump.

 

Are we talking no spark at all? Or just a very weak spark? Have you tested the coil? Just cause it's putting out voltage doesnt mean it's putting out enough. Also check the air gap in the distributor (assuming it's non turbo).

 

The spark is going through your rotor to the distributor shaft or.................the secondary on the coil is the same polarity as ground........which is nearly impossible.

 

Opps sorry, its a 83 280zx NA. The coil is putting out 12-14 volts,, it shouldnt be more should it ? New battery.
No volts or spark jumping from the rotor to the cap terminals.
I did check the air gap during the time I was messing with it, I would have to track down my numbers but seemed close enough, I dont have the numbers right off hand, but i do have them written down somewhere. But like I said I have been thru numerous caps and rotors trying to spend the least amount possible. I did notice that different shops sell different quality parts,,,new cap and rotor is made of brass parts which i like,,,,some even had alum terminals (?)..good heavens..anyway,,,its been a few weeks at least since I have taken any readings,,,I can take some tomm and come up with some more details and numbers, its driving me nuts.,,,any advice on the amount of voltage should be coming from coil the cap ?
And yes I did think of a condenser
I dont see how power would be going thru the plastic to the dist shaft, but at this point, I would go for anything !
Thanks for all the thoughts, this old man needs all the help I can get !!

Thanks Mark

 

Uh... You should see WAY more than 12 to 14 volts going from the coil to the distributor cap. Like 40,000 volts between the coil and the distributor cap.

The coil is a transformer. It transforms the 12 to 14 volts from the electrical system to 30,000+ volts and discharges it to the distributor cap which which sends it to each spark plug and creates a spark.

 

sounds like the coil is shorted out if it's only putting out that much voltage. The input voltage is bypassing the coil windings (which is where the voltage builds up) and just coming out the the secondary side of the coil at the same voltage as it was going in.

That is of course assuming that you do only have 12-14 coming out of the coil tower (to dist).

 

how is the coil hooked up, could be backwards and just sendig the input voltage thru it.

 

Even if it were backwards though it should still fire the plugs. It cuts voltage down to about half when you do that. The car will still run, it just wont have as much power. But if something else is inhibiting spark along with the coil hooked up backwards that might do it.

 

Ok thanks guys, I havent been back to it yet, I have been trying to get my 68 chevy p/u back on the road at the same time, and it runs, So first priority. Ok on the coil, it is pretty well on the cheap side. But yes I agree on the voltage that should be comeing out. I will take a reading tomm. So you say a stock coil should put out around 30-40 K while cranking ? Thanks for the replies

 

Ok put a volt meter to the coil today, probes on frame and coil to cap wire, it reads battery volts. Not the mega volts while cranking or other wise, so out come is bad coil correct ?

 

sounds like you got it.

 

Yea sounds like somthing is rong with the secoundary winding in the coil. thats the only thing I hate about the old coils, you can't really check the resistants of the secoundary.

 

actually you can.

Just hook up an Ohmmeter between the tower and the negative terminal on the coil (coil wiring should be disconnected). Resistance should be in the 8200-12400 ohm range.

 

Thanks for the help guys. I will get a coil this weekend, hope it works, it would be nice to drive it again
Mark

 

Fairlady; I did do as you said, I got no reading what so ever, which means a break in the field. Thanks

 

Jfair are you talking about the primary or secoundary winding?

 

secondary dust. Primary resistance of the coil would be between the + and - terminals of the coil. Primary resistance should be well below 1 ohm.

 

yea all your numbers are correct I wasn't doubting your answer, I just miss read the test points you gave, like it just didn't make sence the first time I read it. sorry.

 

Hey guys its me agian, I bought a new coil still nothing. Am I completely missing something ? Like an inline fuse or something,,this is driving me up the wall,,,go ahead and ask me some questions and I will if I can answer them.
thanks Mark

 

are you still getting primary voltage to and from the coil???

 

Did you pull the rotor and look on the underside where the shaft goes to see if there is any grey dust from arcing through?

 

Ok here goes; I put volt meter on 50 range,,key on..12 volts at terminals and cap tower, well coil wire....cranking it did look like it doubled,,,but on 50 range it shot up to about half way range meaning 25 ish...If I was getting mega wattage it would peg my volt meter ,,correct ? Thats my thinking. So i went to spark plug wire end and no voltage. yea I guess I could have just pulled the wire from the cap,and tested there,but it was fixin to downpour and well, I wasnt thinking straight.
So...voltage doubled, but not going to plugs.

Poo man, I just happen to have the rotor right here and no, no dust,,nice new clean rotor.
I will check for the air gap, but i dont think that is a problem, not after all of these different caps and rotors.

The 83's dont have a computer or something of that nature, do they ?
I mean I can rebuild anything on my 68 truck in the dark, and this thing is throwing me for a loop, and I have been mechanicing for 35 yrs.
thanks for the ears guys if i dont fix it soon ( )
Mark

 

I've only seen a couple of boards crack on that car but the wiring harness connectors are bad on most every one I have seen.

Hence....the suggestion to wiggle the connectors at the ecu.

 

Ok Poo, Im going to sound like a dummy here, but where is the ecu? My particular book is no help at all.( chiltons )not in the index. any help, thanks