73mopar360

Iv done some searching around on the internet but havnt found anything to solve my issue..

I installed an MSD ignition system on my 78' 360.
6A box, Wires, Pro billet mechanical advance dist. blaster 2 coil..
When i try to fire up the car.. it cranks for a second normal, than acts like the battery is dead.. (which it is not) it acts more like there is a short or something somewhere dragging power down.. but i have been over the wiring of eveything multiple times and cant find anything wrong or causing a short..
I do not have any of the factory ignition parts still in the car, I have great spark going all the way to the plugs..
it has fired for a second a few times but wont keep running.. timing adjustments make no difference, It is definitely something electrical.. I just cant figure out what???
Any help, suggestions would be great!
I know its hard to understand and im probably not explaining things real great but maybe someone will grasp what i got going.

RacerHog

Sounds like you wired something to the Cranking Circuit to me...
Once you let go of the key, it's killing the power... ???????????

73mopar360

no key, my ignition and power is on a toggle switch with a separate push button start, it turns over a few times fine than bogs down hard like a battery that is almost dead but still has enough juice to turn the motor over.. but like i said the battery is fine its differently something electrical causing a short somewhere.
the only questionable wiring im thinking is the crank trigger on the dist. both wires are the same color so hooking them up to the box was a 50/50 shot... i have swapped them back and forth a few times and it doesn't change anything.

RacerHog

ok... Then if you got spark... your good on that.... Now lets deal with the cranking issue....
What is the amperage draw when cranking?

What battery?
OEM Location?
New Battery Cables?
Got a good Ground?
Starter Bench tested ok?

73mopar360

Just thought id update, I found the issue.. it was a stupid over site on my part. Basically my timing was way to advanced... that's what was causing the bogging down as if the battery was dead.
The over site was when I removed the old distributor and put the MSD in, I didn't even notice that the flat spade part on the bottom of the distributor shaft and the top rotor point where almost off by 45 degrees instead of pointing more or less in the same direction. So with my drive gear slot pointing in the right direction, the actual rotor was way off... once I realized I had a major timing issue, and what was causing it. I simply turned the drive gear to compensate for the MSD not being aligned like every OEM distributor I have is. This is the first time I have used MSD so I'm not sure if my distributor was just a mistake or if they are all like that... either way, simple fix. just an annoying over site on my part.

TVLynn

Very interesting !! I wonder if MSD is aware of the problem ?? It can cause!!