Electronic ignition / points ignition / MSD Digital 6A & 6AL

[TwoDogs]

In a 1968 Coronet, 440 I have installed (upgraded) to an MSD electronic ignition system. Using wiring diagram that is on page 19 of the instruction booklet, attached. I have an MSD distributor, part number 8546. Cannot get the car to start. Ok, a little back ground, the engine is freshly overhauled and installed, has not ran yet. I know I am getting gas, I know the fuel pump is primed. I have checked spark and am getting it (only checked one plug). I get a nice crank and can hear the compression, but I am getting flames out of the top of the carburetor. I cannot get the engine to start. I have checked to the distributor is not 180 out, its correct. I've also confirmed plug wire to cylinder location *firing order. One thought is to go back to a points ignition to see if I can get it to fire......thank you all for your input.

 

[bigbluedodge]

I would think if you have spark the MSD is ok.
Ignition timing OK?

 

[Don Frelier]

I would pull the plugs, crank it with throttle wide open and put a timing light on it.
No more fuel until you prove out the timing.
If you pull the plugs and hold the throttle open it should not draw in fuel.
I think you need to put a jumper across the ballast resistor as well.
Spark is crisp and blue?

 

[TwoDogs]

spark is crisp and blue. I will confirm the timing via the light, throttle wide open plugs out, no fuel. what will jumping the ballast do for me?

 

[TwoDogs]

Like the red wire in the photo?

 

[Don Frelier]

Yes I believe the MSD is looking for a full 12 volts on the ignition. But if spark is blue and crisp you should be fine

 

[Ceedawg]

Good ground and the right coil. Normal stuff, tdc on compression stroke rotor pointing to the #1 wire. Buddy had a bad coil, fired one plug but not the next, wouldn’t build the spark. No race coils for the street, they burn out. Good way to test dist coil and box, pull dist, ground with a jumper, turn on the switch then give it a good twirl, caution don’t be close to a plug or coil wire, it will jump a few inches nice and blue and sound like lightning

 

[PRND21]

If you’re getting flames out of the carburetor, I’m thinking that you have a timing/firing order/ cam timing problem. One or the other. Fresh engine, who set the cam timing?

 

[TwoDogs]

The engine was built by a local machine shop, I purchased it from them. They said they ran it .....but I’m not so sure.

 

[TwoDogs]

Good ground and the right coil. Normal stuff, tdc on compression stroke rotor pointing to the #1 wire. Buddy had a bad coil, fired one plug but not the next, wouldn’t build the spark. No race coils for the street, they burn out. Good way to test dist coil and box, pull dist, ground with a jumper, turn on the switch then give it a good twirl, caution don’t be close to a plug or coil wire, it will jump a few inches nice and blue and sound like lightning

I’m going to de-mod it all and go back to the original distributor and the points. Removing the MSD electronic ignition. And reinstall the Edelbrock carb. Back to basics.

 

[furyus]

If you’re getting flames out of the carburetor, I’m thinking that you have a timing/firing order/ cam timing problem. One or the other. Fresh engine, who set the cam timing?

I agree. No need to tear everything out. First, MSD needs a full 12 volts. Bypass the balast resistor. Then, if it doesn't start, look at timing and firing order. That is where I found issues when the engine backfires through the carb.

 

[72RoadrunnerGTX]

There should be no ballast resistor in use with an MSD. The MSD ignition sense leads needs to be connected to both Ign1 (blue) and Ign2 (brown) engine harness wires.

 

[TwoDogs]

There should be no ballast resistor in use with an MSD. The MSD ignition sense leads needs to be connected to both Ign1 (blue) and Ign2 (brow

There should be no ballast resistor in use with an MSD. The MSD ignition sense leads needs to be connected to both Ign1 (blue) and Ign2 (brown) engine harness wires.

using the wiring diagram above I would attach the blue and brown wires to the MSD red wire sense lead and completely disconnect the ballast, correct? Thank you.

 

[72RoadrunnerGTX]

using the wiring diagram above I would attach the blue and brown wires to the MSD red wire sense lead and completely disconnect the ballast, correct? Thank you.

Yep

 

[TwoDogs]

Yep

Thank you for the great advice! I also re-read the installation instructions, it clearly states to bypass the resistor. Thanks again.

 

[TwoDogs]

Good ground and the right coil. Normal stuff, tdc on compression stroke rotor pointing to the #1 wire. Buddy had a bad coil, fired one plug but not the next, wouldn’t build the spark. No race coils for the street, they burn out. Good way to test dist coil and box, pull dist, ground with a jumper, turn on the switch then give it a good twirl, caution don’t be close to a plug or coil wire, it will jump a few inches nice and blue and sound like lightning

On my list for today, test the coil. I've got to remember back to basics. Thank you for the tip...

 

[Don Frelier]

Just an FYI, you don't need to ground a distributor for electronic ignition.
But you do need to ground a distributor with points.

 

[TwoDogs]

Good morning Mopar Maniacs....I am back at it after a break with the family for the thanksgiving holiday. I hope yours was a good time, fun with family and friends.

I've taken a bit of a sanity break and am back at the car. I have confirmed the carburetor, jetting and the float level, confirmed fuel pressure at 8psi on a mechanical pump. Re-checked the rechecking of the distributor is 10 degrees BTDC on the number 1 cyc. at the number 1 plug firing position. I can get the car started but cannot maintain an idle which I feel I should be able to do long enough to get the timing light out....but nope. I am so open to advice it stinks.....I am certain that I am overlooking a simple issue. Plus working alone is always difficult....thank you all for your input. Happy Thanksgiving weekend.

 

[33 IMP]

Sounds like a huge vacuum leak. Hose or nipple cap missing? Bad pcv?

 

[TwoDogs]

Sounds like a huge vacuum leak. Hose or nipple cap missing? Bad pcv?

I’m running without a PCV, just two valve cover push in filters vented to atmosphere. I have to have the PCV installed? Thanks