MSD Ignition - No Start

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Travis Mayfield

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Hello! My 68 dart will suddenly not start. It has always started up relatively easy, but it does not have a choke so cold starts were a little tricky, but not too bad.

First, car info:
340/416 stroker
A833 4 speed
Holley 9381 830 competition double pumper (no choke)
MSD ignition:
MSD Digital 6 Plus (PN 6520)
MSD 8388 distributor
MSD Blaster 2 coil

Battery is 1 month old

Two days ago (earlier and colder than normal) I attempted a cold start, couldn't get it going. It started out doing the typical - trying to start, or starting and dying, etc but I couldn't keep it running this time. After about 5-10 tries, it just stopped trying. It cranked fine, but no signs of firing at all. Frustrated, I let it sit until the next day.

Next day mid-day after the weather warmed up, tried again, still no fire. It cranks quickly but does not attempt to start. I figured maybe fouled plugs were a factor, they were probably due for a change anyways, so I pulled them, they were fouled and had gas on them. Replaced with new Champion RC9YC (same plugs as before) gapped to .040. No luck, car behaves the same.

I have confirmed that the carb is squirting fuel, and I have no reason to believe the carb is the problem. I pulled the coil wire from the dist and I have spark there. Pulled a plug wire and stuck a screwdriver in the boot and set it near the block, I have spark there too. To be fair, I have not checked the quality of the spark since I am working on this solo right now, just checked for spark by sound while cranking. That is next on my list.

Could it be the battery not supplying enough power after all that cranking, even though it still turns over quickly? It is a new, large battery (I do not recall the specs off the top of my head).

Thanks in advance for any input!
 
Last edited:
Travis Mayfield said:
Hello! My 68 dart will suddenly not start. It has always started up relatively easy, but it does not have a choke so cold starts were a little tricky, but not too bad.

First, car info:
340/416 stroker
A833 4 speed
Holley 9381 830 competition double pumper (no choke)
MSD ignition:
MSD Digital 6 Plus (PN 6520)
MSD 8388 distributor
MSD Blaster 2 coil

Battery is 1 month old

Two days ago (earlier and colder than normal) I attempted a cold start, couldn't get it going. It started out doing the typical - trying to start, or starting and dying, etc but I couldn't keep it running this time. After about 5-10 tries, it just stopped trying. It cranked fine, but no signs of firing at all. Frustrated, I let it sit until the next day.

Next day mid-day after the weather warmed up, tried again, still no fire. It cranks quickly but does not attempt to start. I figured maybe fouled plugs were a factor, they were probably due for a change anyways, so I pulled them, they were fouled and had gas on them. Replaced with new Champion RC9YC (same plugs as before) gapped to .040. No luck, car behaves the same.

I have confirmed that the carb is squirting fuel, and I have no reason to believe the carb is the problem. I pulled the coil wire from the dist and I have spark there. Pulled a plug wire and stuck a screwdriver in the boot and set it near the block, I have spark there too. To be fair, I have not checked the quality of the spark since I am working on this solo right now, just checked for spark by sound while cranking. That is next on my list.

Could it be the battery not supplying enough power after all that cranking, even though it still turns over quickly? It is a new, large battery (I do not recall the specs off the top of my head).

Thanks in advance for any input!
Click to expand...
I had a similar problem with my MSD at one point. I could not figure it out. I tried everything, I finally ran a ground wire from the base of the MSD box to the negative battery cable. It fired up and as ran fine for the last 2 years with no problems at all. Everyone tells me that the ground shouldn't make a difference, but it did with mine.
 
Consider bad gas. I had a buddy who's Duster wouldn't start. Checked fire, good. Checked fuel, plenty. I insisted it was bad gas. He insisted it was the MSD box, so he bought a new one. He gave me his old one. His car still wouldn't start. Mine still runs great after 20 years. He did put in fresh gas, and it fired up.
 
furyus2 said:
Consider bad gas. I had a buddy who's Duster wouldn't start. Checked fire, good. Checked fuel, plenty. I insisted it was bad gas. He insisted it was the MSD box, so he bought a new one. He gave me his old one. His car still wouldn't start. Mine still runs great after 20 years. He did put in fresh gas, and it fired up.
Click to expand...
A fair guess, but I have been driving it regularly and just filled up the other day.
 
Travis Mayfield said:
A fair guess, but I have been driving it regularly and just filled up the other day.
Click to expand...

You sure you didn't visit the diesel pump? And bad gas can come in that form, as well.

FIRST thing I'd do is do what you have to do to "rig" a test gap you can SEE. This is not that difficult. Get a plug, bend the electrode out. Find an old plug wire. If you "rig" the thing so the coil-to gap wire is "in the air" it can be ANY kind of wire, even bare. If you do this "with your head" you can "rig" it so you can see down through the hood gap

If you have not, pull at least two plugs and see if they are fouled.

If you have spark and the plugs work OK throw a tablespoon or so of KNOWN fresh fuel down the throat.
 
67Dart273 said:
You sure you didn't visit the diesel pump? And bad gas can come in that form, as well.

FIRST thing I'd do is do what you have to do to "rig" a test gap you can SEE. This is not that difficult. Get a plug, bend the electrode out. Find an old plug wire. If you "rig" the thing so the coil-to gap wire is "in the air" it can be ANY kind of wire, even bare. If you do this "with your head" you can "rig" it so you can see down through the hood gap

If you have not, pull at least two plugs and see if they are fouled.

If you have spark and the plugs work OK throw a tablespoon or so of KNOWN fresh fuel down the throat.
Click to expand...
Or, give it a shot of starting fluid.
 
Im not buying the ground wire on the msd box. They ship with rubber isolators and a ground wire comes in straight from the battery. The pcb inside is completely isolated from the chassis.
They will fail to spark if the battery is weak. Charge the battery up fully and give it a try again.
 
MoparMike1974 said:
Im not buying the ground wire on the msd box. They ship with rubber isolators and a ground wire comes in straight from the battery. The pcb inside is completely isolated from the chassis.
They will fail to spark if the battery is weak. Charge the battery up fully and give it a try again.
Click to expand...
You can believe whatever you want. I know putting a ground wire on my MSD box fixed mine.
 
I agree about having a weak battery . We have smoked 3 MSD 6A's in the last 5 years because of weak battery , bad ground , low voltage . MSD's are very voltage sensitive . We switched to Petronix Ignitor II , got rid of the ballast , used their coil and no more issues . Vacuum advance for the street .
 
383Scampman said:
I agree about having a weak battery . We have smoked 3 MSD 6A's in the last 5 years because of weak battery , bad ground , low voltage . MSD's are very voltage sensitive . We switched to Petronix Ignitor II , got rid of the ballast , used their coil and no more issues . Vacuum advance for the street .
Click to expand...

YOU USED A BALLAST W/ AN MSD, WHEN U DONT HAVE TO ?/
I`ve had 4 msd 6`s on 4 diff cars and not one failure or ballast resister------------no brag, just fact.

Anyone run a double strike petronics w/ an aftermarket fuel inj system ??----------
they sound good if a person is buying a new one . -------jmo
 
OK Bob the ballast on an MSD really does not matter. All the ignition wire--whether straight switched 12V or through the ballast---all it does on an MSD is "trigger it on" In other words it's like a relay trigger. That circuit draws so little current that it does not care whether there's a ballast in there or not.

I'm not sure I understand the claim that low voltage "fried" an MSD but I can see, low voltage certainly would at some point stop operation. Just about ANY vehicle built past the era of breaker points igntion needs "more battery" to insure starting than before
 
I used MSD's test of unhooking the coil wire from the dist and placing it near ground, then tapping the white wire from the MSD box to ground and I got a nice blue spark each time. But that doesn't rule out a low battery not supplying enough power while cranking, and that doesn't rule out the distributor being the problem. I have the battery hooked up to a charger now, and then I'm going to try a shot of starting fluid if that doesn't do it. Thank you for all of the replies! I'll report back afterwards.
 
What you COULD have done is measure the "while cranking" battery voltage. Then look and see if MSD has a minimum posted. For "generalities" I used to say 10.5 minimum, This may be out of date for modern EFI/ electronics.
 
67Dart273 said:
What you COULD have done is measure the "while cranking" battery voltage. Then look and see if MSD has a minimum posted. For "generalities" I used to say 10.5 minimum, This may be out of date for modern EFI/ electronics.
Click to expand...

I did look for a minimum voltage, but I could not find a definitive one for my box. Lots of speculation out there, but nothing concrete. Thanks again!
 
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