Diagnosis

mysavioreigns

Famous Member
Well I finally moved everything around and got the distributor (DSII) all set up, started it up and it ran like a champ. Plugs were around .035" - .040". It would run about 3-4 minutes or so, then get real slow, and die. (oh, this is all at idle in park)

So, I regapped the plugs (for the DSII specs) to about .045" - .050". The car was much harder to start, but finally did, and it ran for only about 10 seconds before getting slow and dying.

So, my guess is that the module/coil is not sending enough spark. Could this have anything to do with the ballast resistor I (think I) still have under the dash? This would cause a lower voltage, and could be the culprit. Only reason I didn't remove it is because it was dark :)

I'm running the DSII, 5200, and the GM HEI module. Also for the record, my plugs looked rich when pulled.
 
Too short of a gap is not going to cause it to die like that.

My setup uses a relay to bypass the resistor and I can pull the relay with no noticeable change in idle performance.

Make sure you have power to the module/coil durning cranking.

Heat can cause a module to fail, they usually wont recover but it does happen.

The module grounds through one or both of the mounting holes, just look for the one with a metal sleeve in it and make sure that one is grounded. On mine you can see the 2 ground wires under one of the mointing screws, one wire goes to the black in the dizzy harness, the other goes to a lug near the voltage regulator. Make sure your ground strap between engine and body is in place and in good condition also.

When I first did my DS2 I got the dizzy to the module wires reversed, this would only let it run at higher rpms and was hard to start. These are the correct colors in the correct places. There was one 'how to' thing that was backwards and a few that were not clear.
hei2.jpg
 
Steve,

The HEI module needs 9v min to operate. If you are using the Ballast resistor still the voltage will be too low after a short period of running @ idle.

It will also cause hard starting.

I had the exact same problem you have. I had a "duh" moment, and ripped the resistor out. Was 100% better the moment I did that.
 
Bort62":1n4k0y8s said:
Steve,

The HEI module needs 9v min to operate. If you are using the Ballast resistor still the voltage will be too low after a short period of running @ idle.

It will also cause hard starting.

I had the exact same problem you have. I had a "duh" moment, and ripped the resistor out. Was 100% better the moment I did that.

Good thought, after extended cranking system voltage could easily be low.

Easy way to test for that would be to throw a charger on so battery is not going to be weak.

I do recommend getting rid of the resistor but was thinking it was not your whole problem unless its just a system voltage thing like Bort said.
 
mysavioreigns":2jm9f1yt said:
Also for the record, my plugs looked rich when pulled.

8) it sounds to me like you have a carb issue here, and not an ignition issue. make sure the carb isnt flooding.
 
The ground might be the problem as you mentioned as well TJ. Currently I have one of the grounds wired back to the the black wire coming off the distributor (which is thus grounded through the block). I can easily run another one to ground somewhere on the body, but I imagine the module would not work if it wasn't grounded, correct?

Thanks bort, will do.
 
Missed your post rbohm. I've suspected the carb many times, may have some problems. It just doesn't feel like it should. I bought a rebuild kit, and I'll check the float as well.

I am getting 2.5 psi from my regulator in-between the pump and the filter.
 
Isn't the ballast resistor wire on a '66 Mustang the cloth covered wire?
I don't think you will find a ballast resistor if you go looking for one. May have to run an alternate wire from ignition switch to the coil.
Doug
 
Let me just re-iterate taht the GM module will not work properly with the ballast resistor or resistor wire.

Give it a solid 12v, and see what happens...
 
Bort62":3sks8qys said:
Let me just re-iterate taht the GM module will not work properly with the ballast resistor or resistor wire.

Give it a solid 12v, and see what happens...

what he said...

the plugs will be black if the spark is jacked up. (technical term) :wink:

you still might have a carb problem but get 12v to the module.
 
I recently picked up a DSll & Module at a "junkyard", but have not installed it as yet. While on this subject, and not meaning to hijack the thread, will the "pink" resistence wire work with a 1.5ohm coil and the DSll ??? The reason I ask is that from what I have read, you can still use the pink resistence wire with a 1.5ohm coil on the Petronix ignition system; which is my current set-up! It works fine with the Petronix l system. What about a 1.5ohm coil & resistence wire with the DSll? Does anybody know? Thanks, Jim
 
Just take the damn wire out. It's not that hard...

The electronic ignitions & corresponding coils are designed to run @ 12v. The resistor wire is designed to drop the voltage below 12v.

Fundamentally incompatible.
 
if you're skeptical, run a jumper wire.

Meaning, get a length of wire the same gauge as the lead to the coil and tap upstream of the pink wire. Run this through the firewall to the module/coil. There is your switched 12V power.
 
The pink wire is connected via a bullet connector. It can be unplugged, and a substitute 14ga wire plugged in its place also using a bullet connector. I believe the pink wire becomes brown after passing through the firewall. Anyhow, disconnect at both ends and run your replacement wire the entire length.
 
Thanks for the advice on the "pink" resistence wire. Like I mentioned, I do not have a problem with my current set-up (Petronix l & 1.5ohm coil), but when I do try installing the DSll in the future, if there is a problem, I will start by-passing the pink/resistence wire. Jim
 
Ludwig, I will try and see if I can find where it was that I read that the "pink" resistence wire can be used inconjunction with a "1.5ohm" coil! Over a year ago when I installed the Petronix l ignition, and did not feel like removing or bypassing the resistence wire, I read that you can use the resistence wire with a "1.5ohm coil". Since I was planning on replacing my "old" coil anyway, I installed the 1.5ohm coil just for that reason. I will see if I can find out where it was that I read that; it may have been on this forum or possibly even Petronix's site???? Jim
 
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