Won’t start No Spark.

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E Satterfield

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Last year was heading to a car show and my 440 quit running. We established by the side of the road that there was No Spark. The car is a b body with a 440+6. At that time it was using an aftermarket magnetic pickup distributor and an MSD CDI box. I first replaced the pickup with No Results. Then a new MSD (Street Fire) box and a Pro Form factory look distributor and the car started and ran for several days. A new no start condition arrived again same issue No spark. After reading a bunch of bad reviews on that particular distributor I chose to return it and purchased a Summit branded billet one. Car started and ran all the rest of last season. Today I wanted to get the car from the garage and again No spark. I have no spark from the coil when cranking the engine. If I un plug the trigger wires from the distributor and jump them. I can make the coil fire. But not always about 5 out of 10 manually.Wiring looks ok. Do you think I could have yet another bad distributor? Possibly a bad coil ( MSD high vibration) or ignition switch? Running out of ideas. Thanks to all in advance
 
You are checking for spark right out of the coil, ?

This may or may not be the same old saw about ign1 / ign2. Are you aware how Mopar ignition systems work?

First thing I'd do is pick up the ign supply line to the ignition system, which would come from the old ballast resistor connections, and make certain that you have power there BOTH with key in "run" position AND in "crank" position.

If you do and it will not start, make certain you do NOT have anything connected to coil EXCEPT ignition system wires. No radio capacitor, no tach, no nothing else

If you have power and no spark, check connections generally. You might try some other coil. Coils do not need to be mounted, or grounded, to try them.

If you suspect ignition switch, I would just "unwire" the ign unit temporarily and just "hot wire" it direct to say, the starter relay "big stud"
 
I’m new to the world of Mopar and also to MSD CDI systems. Are these boxes voltage specific meaning if they have low voltage they won’t work. Reason I ask. The battery was a little low from sitting all winter unattended. After trying to get it running. I had to run an errand with another vehicle meanwhile I had not removed the battery charger from the car. When I returned it started. Thank you for taking the time to reply. Eric.
 
Short answer is YES. Low voltage or even incorrect voltage will play havoc with electronic systems.

Dad's lesson also always rings in my ears. Check the ground. More problems are created by bad/faulty grounds.
 
I’m new to the world of Mopar and also to MSD CDI systems. Are these boxes voltage specific meaning if they have low voltage they won’t work. Reason I ask. The battery was a little low from sitting all winter unattended. After trying to get it running. I had to run an errand with another vehicle meanwhile I had not removed the battery charger from the car. When I returned it started. Thank you for taking the time to reply. Eric.

I would certainly get the battery up. You can monitor battery voltage and crank the engine. If the battery is below about 10.5 when cranking I'd stop there and get it charged

Some background. First, if you don't have a factory manual, run over to MyMopar and download one, free

The MSD CD (6A or whatever) hooks up main power with large black ground and large red straight to battery. It is "triggered" on my a small red wire which goes to switched power.

Originally your Mopar ignition switch fed TWO separate power sources into the engine bay. IGN1 is "run" is powered ONLY when the key is in "run" and not "start." This goes DEAD in start

The other end of the ballast resistor connected to coil, and had two wires, one leading to coil, the other the "bypass" or IGN2 coming from the ign switch. THIS IS the only power to ignition during start. This wire comes alive when key is twisted to start, just like the yellow feeding to the start relay. BUT THEY are separate contacts in the switch.

So the (usually brown) IGN2 "bypass" and the (usually blue) IGN1 "run" need to be tied together to provide both start and run power. Access your ign and make sure it has power in both key positions.
 
Thank you for the information. It cranked a little slower than it normally does when the car has been driven on a weekly basis. But didn’t seem low enough to not start. I didn’t build this car as it already had the MSD parts on it when I purchased it and it seemed to work well for the previous owner because it has been that way for a few years before he sold the car to me . ( First Mopar by the way now we have two!..lol ) This is why I went back to these components when it quit running the first time last summer Today I did jump the connector that triggers the coil through the box . As stated earlier. I would get weak spark about half the time. That’s straight from the coil wire to ground .But had no spark with the wire in the same position engine cranking. I checked both sides of the ballast with my meter and had equal voltage of both connectors .I feel stupid especially yelling at the wife when she said “ Does it need a new battery?” I thought I had read something about those systems being voltage sensitive.
 
Should not be "all" that sensitive. Go to the MSD site and look up the specific system, somewhere on there, MSD has troubleshooting hints.
 
Check the reluctor air gap inside the dist. Should be 0.008" [ max ] for the Mopar, & if you are using that abortion that MSD makes, 0.010".
 
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