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el Dizzy is touchy?


Lozer

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So I have this 78 single pickup el dizzy wired up with an Hei Module. Works ok but if I adjust the timing it seems to have dead spots where it just dies and wont run. Wondering if anyone has any advice or experience on this.

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I was fighting some issues with misfires under load around 3k.. it was something funky with the dizzy. I swapped it out and all was well. 

 

It didn't feel loose, or anything but I'm no dizzy guru.

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when you installed dizzy you surure the spindal was set at 11/27 and the mount lets you get the rorot righ in the middle of the timming plate?

 

If you were directing this question to me, yes timing was spot on. I thought it might be something to do with the advance pulling it way too far advanced or something. I tried swapping modules, carbs, plugs, wires. rotors. I finally dropped the advance vacuum host and that helped, but it felt like I had a loss of power. Swapped to a spare dizzy.. boom fixed.

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So I have this 78 single pickup el dizzy wired up with an Hei Module. Works ok but if I adjust the timing it seems to have dead spots where it just dies and wont run. Wondering if anyone has any advice or experience on this.

 

 

 

Seems. Lots of thing 'seem' to be something but can just as well be something unknown or thought of.

 

 

Is the air gap between reluctor and the pick up coil adjusted to between 0.010" and 0.015"????????

 

Are the two wires from the dizzy free from interference. I'm saying, could this magnetic signal to the G and W terminals be receiving outside interference from a plug wire? 

 

Do you have a tach??? If there is an interruption of power (loose wire, the engine vibrates at different rates) or failure of spark, the tack will drop or become erratic. Could even be the ignition switch.

 

If it's just a miss fire, the spark jumping off to ground then this is not the dizzy's fault. Double check ALL wiring. The ground is just as important as the power wire to the HEI.

 

Lots of things make it harder for the spark to jump the spark plug gap. Compression pressures vary with throttle. Make sure the cap/rotor and wires are in good shape. Are the plugs clean on the outside? It's important that the spark plug is the easiest path to ground.

 

Fire it up after dark and take a look. I found my coil was cracked because there was the odd blue flash when revving the engine.

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It seems some stock coils just don't like to work with the hei, I had to replace mine with an accel superstock, when that took a shit I put in a 200sx stocker. The accel failure seems to have been a fluke, as the one in my toyota with gm hei still works perfectly.

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The Nissan box or matchbox has circuitry that limits total current draw through the circuit. If using an HEI maybe this doesn't have this feature. In this case get a GM coil that the HEI is matched to. Otherwise, all the Nissan or GM modules do is switch the coil negative terminal on and off to ground. Nothing magical to this.

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The Nissan box or matchbox has circuitry that limits total current draw through the circuit. If using an HEI maybe this doesn't have this feature. In this case get a GM coil that the HEI is matched to. Otherwise, all the Nissan or GM modules do is switch the coil negative terminal on and off to ground. Nothing magical to this.

FYI, the coil that goes in the dist with a GM HEI, is mounted in the cap.  Get a good canister coil that has the proper resistance for the HEI module (same as the one for the match box dizzy.) 

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I mentioned this because I don't know what the GM coil resistance equivalent is. If there is any connection between an HEI and a coil failure Nissan or after market, it may be they are not matched to each other. I would never run an after market coil. they are over priced and work the same. Or less.

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After diggin around Ive found that the hei uses a .3 or under 1 ohm ohm coil.

 

scroll about halfway down and see the remote coil Accel lists the ohms. 

 

I also dug up a test article on different ohm coils with hei control units

 

http://www.jalopyjournal.com/forum/threads/ford-gm-hei-coil-question.617596/

 

Credit to Bubba at the Hamb.

 

OK, TOOK ME A MINUTE BUT NEEDED TO BE DONE I GUESS.

The HEI came as a federal mandate to increase tune up mileage ( for clean emissions) and was a first from the Delco guys in regards to high energy ignition systems and was a home run from the first day forward.
The ignition offered high energy at 5.5 to 6.0 amps of primary current controlled by the module. Module also offered a varying dwell to prevent the igntion coil from overheating using low dwell at idle ( 15 degrees) and increasing with rpm to 30 up the rpm scale.
The orginal design was to use a .5 ohm untapped coil and isolated the primary and secondary windings ( caused some problems when left at high demand).
This discussion concerns the ignition coils used with the HEI.
I tested three coils this morning with the waveforms shown .
1- .5 ohm (oil filled) ignition coil. Unit ws single firing a 25,000 test plug and used as waveform shows 5.8 amps clipped with current limiting ( hence the flat spot at shut of of control) and used a preset time of 3.6 mili sec to get er done. This is a normal function of a properly working high energy ignition system. You can hear see and smell the energy ( and feel if your not careful)
2-1.5 ohm coil...... Unit still fires a 25 kv test plug but you can hear the difference in enegy, waveform shows a decrease in current to 3.0 amps . ( A new point ignition runs at this decreased level )
3-4.0 ohm coil, would no longer fire the test plug and using a standard plug spark was at 2,000 volts and 1.5 amps .....this one wouldnt owrk very well if at all!

Hope this clears up some mis conceptions in regards to HEI module control
The hamb is a great place for sure.........clear.png

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point coil made to run on less than 12volts  usually 6 volts on Datsun due to the points needed less current otherwisr they burn up. that's why the ballast resisitor and prevent coil from getting HOT. about 1.2 ohms  or more. Dtasun 510 is about 1.6ohms

 

HEI type coil  made to run on 12-14volts  no ballast.  most these are in the .7 ohm range or maybe even less

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So basically the same as the matchbox. It also varies the dwell time and current but also shuts off if matchbox is on but engine stalled or off. Beware drawing conclusions based on sound and smell. Things are much different inside the engine.

 

I think the cost of the HEI makes this a very attractive option. If any doubt, get the matching GM coil.

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Understandable Hainz, I was just using them to confirm my suspicion that hei modules don't do well with higher ohm coils.

 

Confirmed. I swapped in my points  1.5ohm coil and it fixed the dead spots.  so in conclusion with the stock hei modules I would change the diagram to read 1.5 ohm coil.

 

Im gonna see if I can dig up an old hei coil I have hiding in the shed and see if that further improves idle ect.....

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You can still use a point coil and ballast with a  matchbox dist .  Its just keeps the coil from over heating.  I would assume this the same with the 1st gen Nissan dist also.

 

My pertronix conversion was acting up on a early Mitshibitshi dist I had.. Found out the vaccume adv was locked up. Was like a new car after i installed another dist.

 

 

To make this simple use a HEI type coil and NO BALLAST and should work perfect

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