Help with MSD ignition system diagnosis

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str12-340

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I have a 340 with an MSD ignition system - Probillet distributor and an old school 6AL box (NOT DIGITAL!). I've used this on my Dart for 15 years or so and it has operated flawlessly. The engine now cranks, but no fire. Before I send off the Box and dizzy to MSD for diagnosis and repairs, I want to make sure that the problem is not in the wiring to the components first. Can someone suggest a set of tests that should be made to do that? (e.g.: test for 12v at the following locations with the key on or off, etc.). About a year ago I replaced all the under dash wiring including the ignition switch and I want to make sure that system isn't the source of the problem rather than the MSD components.

Thanks for any help...
 
I've called MSD Direct with customer cars and they will just sit there on the phone and talk to you through... I only had to do it that one time and they were great about being patient it seemed well worth the effort...
 
the msd distributor will need 12 volts during cranking and running......there is a red wire that provides thats.....not the red wire that goes directly to the battery....
turn key on....red wire should have 12 volts.....crank it...red wire should have 12 volts...

large red wire goes to 12 battery source....large black goes to a good ground.....orange wire goes to plus side of coil.....black wire goes to negative side of coil...
make sure the distributor is plugged into the msd box....
 
Wait a minute, depends on what distributor he has. He said pro-billet which I think is just the standard two wire like the original was. If its a ready to run (HEI) you will need 12v to it.
 
LIke I said, it's a pro billet distributor (8534) not the ready to run distributor (which I believe wouldn't use a separate 6AL box...)
The Guy at MSD help line has been really helpful - I'm trying to make sure I don't have a wiring failure before I send the box and dizzy to them for testing.

Thanks for the links and advice so far!
 
You shouldnt need to send them out for testing. There are countless pages on the internet with instructions on testing them. You can test a 6al on the bench in literally a couple minutes with just a couple jumper wires and a battery.
 
Plug a factory electronic distributor in and spin it by hand with the key on see if you have spark. you don't need a plug just strip the wires and stick them in.

Put a long spark plug wire on the coil then I usually look for an innocent by stander and tell them to hold the end of the wire. I already got my wife , son, and one daughter in the past. so you only get so many chances. use them wisely. This will eliminate the Distributor question.
 
Plug a factory electronic distributor in and spin it by hand with the key on see if you have spark. you don't need a plug just strip the wires and stick them in.

Put a long spark plug wire on the coil then I usually look for an innocent by stander and tell them to hold the end of the wire. I already got my wife , son, and one daughter in the past. so you only get so many chances. use them wisely. This will eliminate the Distributor question.


COIL ???????
 
You can test a 6al without a coil. If it were me I would start by checking for voltage, then swap in a known good coil, then test 6al box and distributor.
 
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