L24 Pertronix Ignition Dwell?

[DatsunMotorSports]

1971 240Z, L24.

The Dwell is sitting at 22 instead of the 35-41.

 

The pertronix unit has counter sunk screws on both sides to eliminate adjustment(not that I have any clue if it would make a difference). Im not sure how to get any more coil saturation. Im having a hard time accelerating to freeway speeds and using the upper RPM range. I set my idle, set my timing and decided to check dwell after everything checked out. This just doesnt sound correct?

 

HELP?

[datsunaholic]

There's no way to adjust that. The "dwell" of an electronic system is set by the electronics. On race-application ignitions, it's adjustable but it's simply not possible with the pertronix. Moving the base plate simply will change the timing, not the "break" angle.

 

It sounds more like you have a coil that isn't correct. Pertronix setups need a high-impedance coil (so they don't run too much current) and if you are using a low-impedance coil with an external ballast it would cause problems.

 

Though that might not be a coil issue at all, could be too much static advance.

[DatsunMotorSports]

There's no way to adjust that. The "dwell" of an electronic system is set by the electronics. On race-application ignitions, it's adjustable but it's simply not possible with the pertronix. Moving the base plate simply will change the timing, not the "break" angle.

 

It sounds more like you have a coil that isn't correct. Pertronix setups need a high-impedance coil (so they don't run too much current) and if you are using a low-impedance coil with an external ballast it would cause problems.

 

Though that might not be a coil issue at all, could be too much static advance.

 

By adjustment I meant air gap not degree position.

 

As for installation and coil there were not very good instructions so I did a guess where it goes game.

 

I left the original ballast resistor in place. I have a MSD Blaster 2 coil. The GRN/WHT and BLK/WHT have not been moved and are still connected to the ballast. The other BLK/WHT wire is on the + coil post. The BLK wire is on the - coil post and so is the BLK wire that was for the old points. The pertronix RED and Black leds are on the + and - respectively.

 

If I messed up feel free to point out my flaw. Im sure that is the case.

 

Static advance? The Dwell should be the same despite ignition timing, right? Its pretty static I thought.

 

Thanks

 

Ray

[datsunaholic]

Air gap and dwell don't have any correlation, not on an electronic setup. What having too much gap will do is decrease signal to the module (which is all part of the same unit) so that it will occasionally NOT fire, or be delayed in firing. It doesn't cause a weak spark. Dwell is a function of a points system... it's how long the points stay closed measured by angle of rotation. You could adjust that by changing the air gap, since a closer gap created longer dwell. But the longer dwell also changed the timing slightly, AND as the cam rider wore down the gap would close up and then you'd get no spark at all. With electronic system, this never changes, unless you had a race-type programmable ignition.

 

I can't tell if your wiring is right or wrong, the wire colors don't match what they should. In fact the symptoms almost sound like the coil is wired backwards, but that would have fried the pertronix.

 

Should have a constant 12V to one side of the ballast (with ignition on). The other side of the ballast should go to the coil (+) terminal- there should be another wire on that side of the ballast that gets 12V only when cranking (Start).

 

The Pertronix wires, the black goes to the coil (-) terminal. The red, depending on which set of instructions you got, should either go to the always-12V side of the ballast or the (+) side of the coil... it probably would work better on the 12V side rather than the resistor-dropped side.

 

THAT'S IT... unless you have a tach, then that lead also goes to the coil (-) side.

[hughdogz]

To add to datsunaholic's comments, I'm not pretending to be an expert on this or anything, but as far as the wiring goes, we have a "How to" write-up thread: Electronic Ignitions for L-Motors (4 cyl)

 

 

 

Hope this helps...

[DatsunMotorSports]

That helps,

 

Something is NOT correct with my wiring.

 

 

I will see about re-wiring this and seeing how it works out.

 

_________________________________________________________-

 

 

Found what I was looking for:

http://www.zhome.com/ZCMnL/tech/ZXPertronix.htm

[hang_510]

check the impedance of the ballast, may be cracked (or is the tape for another reason?)

[banzai510(hainz)]

Feel if you ballast resisitor is getting hot. If it is you should put the stock coil back in.

 

Maybe you have carb issues. If you have a spare distrbutor I maybe would swap that in. to rule out electrical issues

[I'm BLUE]

What Type of Plugs do you have ? ( Auto-lites would not work past 4,000 without kicking like a donkey in my 240z , NGK's will get mine all the way through in no time ! )

 

Carbs are jetted and set-up/Tuned correctly ? ( look down throat and make sure carb "sprays" and doesn't squirt a stream or drip at all. ( unless you have SU's then that's easy , open those baby's up and clean them out as well as reset. ) In Webber's You can also see the size of the air-bleed jet's from the top after spraying some carb clean down the throat and looking at the size. This would be important to investigate the idea of people "piecing" together webber carbs instead of using a matched set or at least jetted correctly. )

 

Does your Vacuum advance work in the distributor or is it leaking/stuck ?

 

Plugged Muffler ?

 

Airation in Fuel System ?

 

Fuel Pressure ?

 

Size of Tires ? ( this is critical , mine had 205/60/R14's when I bought it , they were bald , and is now a lot zippier with 195/60/R14 , I MEAN A COMPLETELY DIFFERENT CAR and same gas mileage :D

[datzenmike]

Looks like SUs to me. Unscrew the the black screw tops and check that the damper oil is full. The oil works like a shock absorber. If one or both are low it will allow the piston to lift far to fast on sudden acceleration and will cause off idle stumble and lean mixture when it should be richer.

 

Remove the air filter(s) and reach into the carb with a finger and lift the piston. You should feel an even light resistance with no loose spots. Any free play indicates low damper oil.

[I'm BLUE]

Looks like SUs to me. Unscrew the the black screw tops and check that the damper oil is full. The oil works like a shock absorber. If one or both are low it will allow the piston to lift far to fast on sudden acceleration and will cause off idle stumble and lean mixture when it should be richer.

 

Remove the air filter(s) and reach into the carb with a finger and lift the piston. You should feel an even light resistance with no loose spots. Any free play indicates low damper oil.

 

+1 , and if they stick or do not return right away you'll need to open up and clean them/reseal them. ( Mine were a bit sticky on the rear SU on my 240z )