Hey Fellas,

Thor's amazing old Dart is now having ignition problems. It's a 74 with an 80's ish valiant SL6 with electronic ignition. Was running great and then all of a sudden...

The starter cranked and cranked but had a white spark out of the distributor to spark plugs and then also out of the coil. So I replaced the ballast resistor, and both still had a white spark. Then had the ECU tested and it was bad so I replaced it and had an infrequent white spark out of the coil. Then I replaced the coil and now no spark, just a massive static shock.

What have I done? Does anyone have a better trouble shooting method than the ambiguous Haynes? Damn thing doesn't tell you what to do when you have no coil spark. I'll go through all of the connections again, but it would be nice to narrow it down if one of the new parts is bad or not. Mann electrical problems are the worst.

Thanks in advance, you guys are all amazing,
--Miike

Take your time and do some measurements with a volt meter.

What is your voltage before the resistor?
What is your voltage after the resistor?
What is your voltage at the coil?

Let us know.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Hey Ted,

I have to go and buy a meter, so I'll get one tomorrow and let you know. Thought I had one, can't find it.

Thanks for the quick reply,
--M

You just threw parts at the car without a valid reason. You had spark, so what if it was white, blue, pink, etc. Was it about an 1/8 to 3/16 inch long? If yes, that was not your problem. It is entirely possible the "new" ECU is bad.
Remove the dist cap and crank the engine. See if the distributor rotor turns smoothly. It is possible the gear stripped a tooth. Pull #1 spark plug and put the piston at top dead center (doesn't make any difference whether it is on compression or exhaust) and put the timing mark on the crank at zero. Look at the distributer rotor, and see if it points at either #1 or #6, if not either the timing chain jumped or the distributor gear broke. While the plug is out make sure it is not black, as that carbon will short the spark without firing the plug.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Thanks Father Charlie
It's the common sense things like your troubleshooting that I lack. I'll learn someday. I'll try putting the old ECU back in too to see what I get.
That's an easy swap. Could the radio supression thing on the coil be grounding out the coil connection if it is bad?
Thanks again,
--M

We all had to learn, at one time or another. I have had 50+ years, and still learn many new things. The most important tool is not in your tool box, it is on your shoulders.
You need to think logically, not just through parts at a problem. That can get expensive, and still not solve the problem.
Yes the noise suppression capacitor can ground out the coil, if it is shorted. You can just disconnect it, to see if it makes a difference.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Hello Again.
Finally got a voltmeter. Checked and I have continuity through all of the wiring between the ECU, Ballast Resistor and ECU so wiring between components seems to be OK. I'll go check actual voltage readings to be sure once my battery is fully charged.
I'm getting a single spark every time I turn it over and then nothing still. Checked the rotor to cylinder position and that seems OK too.
Could it possibly be that I have a bad pickup coil assembly? I seem to have power all the way to the coil, but nothing telling it to send a spark.
Man Why couldn't it have been a mechanical fix... Evil Electrical stuff

Thanks again for all the help.
--M

It could be the pickup coil. Unplug the distributor and measure the resistance between the two distributor wires and report back. If memory serves the resistance should be a few hundred ohms. Not shorted, not open.

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Joshua

So the pickup coil reads 1 ohm when I plug the meter into it. Both when the lobe is in contact position and in between. Not sure what that means. I'm guessing that it conducts current.

Man electrical problems stink.

Just so you guys know. Mopar people are awesome! I've been on the VWVortex forum and those dudes are RANK to say the least. Just plain stupid. Every post I read here is responded to in a most civil and nice guy manner. Thanks for puttin up with us tinkering fools!

One other thing I was wondering. Is there some kind of component referred to as an "exciter" of some sort that contains a charge from the battery to assist with starting?
Doubt this is it, but I'm running out of components to check although I know there's more I'm missing somewhere.

No.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Pickup coil should read more then 1 ohm. Go to your local part store, with your meter, and measure a new one, and compare readings. Then you will know what a new one should read. Myself, I have an old Sunpro tester, that has two led lights. It just connects to the pickup, and if the pick up is good, the lights will blink when the engine is cranked. It can test most any sensor on a car, and was inexpensive. I was going to recommend it as an "essential" tool, but it is no longer available.

PS: Check the gap, between the lobe on the reluctor and the coil. Should be about .008 with a brass feeler gauge.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225