Ignition Query

[Rob Gaskin]

I run my car (72 240Z) with Lumentition Electronic Ignition and a Micro Dynamics Coil.

I still keep the ballast resistor in circuit and everything is fine.

My coil reads 'For use with all 12v ignition systems' so I'm assuming it's a 12v coil. Is it running at optimum performance with a ballast resistor in circuit - I doubt it?

Last week I tried a 280ZX distributor and coil - ballast resistor out of circuit - fine no probs.

So I tried my existing system with ballast out of circuit and it ran fine but the Rev-counter doesn't read above 4k!

I can't tell any difference performance-wise with the ballast resistor in or out of circuit!

Any clue why the rev-counter plays up without the ballast resistor?

Coil:

Micro Dynamics High Energy Coil - Better Cold Start Up - Increased Power | eBay

 

[tel240z]

Rob it says in your link that the coil needs to be run with a ballast resistor or damage could be imminent i suspect its a 9 volt jobby

 

[morbias]

If you upgrade to a 12v coil then you need to keep the inductive loop that lets the tach function, ie. you need to keep a resistor in line with the tach.

 

[Rob Gaskin]

Rob it says in your link that the coil needs to be run with a ballast resistor or damage could be imminent i suspect its a 9 volt jobby

Doh

Thanks Terry so I'll just keep it going as I have for 10 yrs! I have been told on more than one occasion to take the ballast out of circuit!

The confusing bit is the 12v notification.

 

[zbloke]

FWIW

I run a 280ZX dist, Micro Dynamics coil and no ballast resistor, just the wires that went to either side of the ballast resistor joined together, my tacho works fine

When I did try to run it with the ballast resistor in place I got a misfire at high revs, remove and join ballast resistor wires, it pulls all the way to 7K

 

[SKiddell]

The error is the assumption that

'For use with all 12v ignition systems'

means its a 12 volt continuously rated coil

“For use with a 12 volt system” doesn't necessarily mean it’s a 12 volt coil

Yours appears to be a 9 volt rated coil so it still requires a ballast resistor to drop the voltage during continual running.

If it were a 12 volt rated coil then removal of the ballast resistor would be fine and in fact beneficial

 

[Rob Gaskin]

If you upgrade to a 12v coil then you need to keep the inductive loop that lets the tach function, ie. you need to keep a resistor in line with the tach.

When I ran the 280ZX Dizzy and Coil (not mine but kindly lent for evaluation) without the ballast resistor the Tacho worked fine.

So the tacho needs to 'see' the 12v drop across the coil or appropriate 'ballast coil'+ ballast.

 

[bigblock]

For anyone who wants to check what coil they have.To add to attachment most older single electronic coils(not referring to coil on plug) are usually under 1ohm across -ve and +ve.

 

[andrew muir]

I have just fitted a pertronix ignition system and a flame thrower 3.0 Ohm coil to my car and I am experiencing the exact problem Rob has; the tach works to 4000revs then drops to zero. I have removed the ballast resistor.
Have I got the wrong coil for a non ballasted system?
Should I have recieved the 1.5 Ohm coil instead?
I could easy put the ballast resistor back in and suspect this will cure problem but will that damage coil or upset ignition system?
Cheers
Andrew

I run my car (72 240Z) with Lumentition Electronic Ignition and a Micro Dynamics Coil.

I still keep the ballast resistor in circuit and everything is fine.

My coil reads 'For use with all 12v ignition systems' so I'm assuming it's a 12v coil. Is it running at optimum performance with a ballast resistor in circuit - I doubt it?

Last week I tried a 280ZX distributor and coil - ballast resistor out of circuit - fine no probs.

So I tried my existing system with ballast out of circuit and it ran fine but the Rev-counter doesn't read above 4k!

I can't tell any difference performance-wise with the ballast resistor in or out of circuit!

Any clue why the rev-counter plays up without the ballast resistor?

Coil:

Micro Dynamics High Energy Coil - Better Cold Start Up - Increased Power | eBay

 

[Mr.F]

Found this on ZHome.com - suggests that this is the correct way to wire up the Pertronix and maintain the tacho working:

 

[andrew muir]

Thanks for Mike
But the drawing is assuming the standard coil is used.
I think I may have fixed the tacho issue.
Before there was a little capacitor type device which was connected to the distributer body, earthing wire? I have connected the other end to the negative terminal of the coil, and revcounter no seems ok.
Do you know what this is?
However have a problem with the engine not reving above 5000rpm, could this still be a timing issue? or something else?
Cheers
Andrew

 

[johnymd]

I know this is a very old thread but I thought id add so info of what I've found.

My ratty car was all factory wiring and I dont want to start cutting it about but wanted to go electronic. I fitted a 280zx dizzy a while back and simply shorted to 2 wires for the ballast and run a + wire from the coil to the C terminal on the dizzy. The old - from coil goes to the other terminal on the dizzy. Very simple and all worked perfect including the Tacho.

I then needed a good 280zx dizzy for another car so fitted a petronics module to a spare dizzy and connected it up just as the 280zx dizzy was connected. Then fitted a 3.0 ohm flamethrower coil that I had. Car runs and revs fine but Tacho bounces about once you reach 4k. Any ideas of a simple fix?.

 

[jonbills]

I know this is a very old thread but I thought id add so info of what I've found.

My ratty car was all factory wiring and I dont want to start cutting it about but wanted to go electronic. I fitted a 280zx dizzy a while back and simply shorted to 2 wires for the ballast and run a + wire from the coil to the C terminal on the dizzy. The old - from coil goes to the other terminal on the dizzy. Very simple and all worked perfect including the Tacho.

I then needed a good 280zx dizzy for another car so fitted a petronics module to a spare dizzy and connected it up just as the 280zx dizzy was connected. Then fitted a 3.0 ohm flamethrower coil that I had. Car runs and revs fine but Tacho bounces about once you reach 4k. Any ideas of a simple fix?.

I think +ve goes to the B terminal and coil - ve goes to C terminal, so is it possible youve wired back to front?