Not getting spark after shutting motor. I need some help troubleshooting MSD system

crazypete

All my crevices are greased.
Oct 22, 2004
930
4
18
Arlington, MA
So today I take the stang out for the first time since my gt-40p's. The ignition system has been untouched since 1 1/2 years, always working strong. 85 Distributor going to an msd al6 feeding an old old 60K volt (?) jacobs coil.

I idled it 20 mins at bottom of drivenway, then 10 mins at the top (still no problems) and I drove down the street, I see the fuel guage is low. I pull in to the station, tank and then crank and it doesnt kick in. I give it some gas, still nothing. Crank crank crank. I look down into the carb and I see gas shooting out the acc pumps when the throttle is opened. So she's getting gas. We boost the battery anyway and it cranks faster but still no dice. I attach a timing light to a wire and crank... no flash. So it's no sparking. I get it towed home and start dissecting it.

Coil: I get the fender open and do the MSD touching pickups together trick and no spark (I have no white wire). I detach the coil leads and (is this how to test the coil?) touch coil + to batt+ and coil - to batt- with a grounded plug on the end. I see a little baby barely visible hair strand thick spark, not that fat blast with a tick sound I'm used to. So I guess the coil works somewhat.

Box:I detach the msd and the + power lead to - ground lead is 13 volts, + "key on" wire is 13 volts to the ground lead (with key on). I touch the magnetic pickup wires together again and again and no spark. I detach the MSD box to coil leads and wrap an analog voltmeter across them. I touch the pickups together a few times and I dont see a blip. I reverse the coil leads on the voltmeter probes and try again. Still nothing.

Can I safely assume my MSD box bought the farm? Why would it do that when I shut the car? Shouldnt it do that in motion or when water splashes up (It rained so there was puddles and such)? If I do need to replace it, is there something more appropriate for a street low compression motor than this al6? I liked it but they are expensive!

Thanks for looking all

~Crazy Pete
 
Yeah, the automatic acts as a good rev limiter on it's own (5400 or so) .

So I take it MSD is still the way to go then? Did I test the coil correctly?

How about coils? Any of those better than others? This jacob's is about 6 years old.