stumbling 502 update....MSD box not grounded???

[4speedfunk]

Thanks everyone for the advice. After doing some investigating...I discovered that my BG 850 was really a 750. Not a problem....I'de rather give up some top-end for a better signal and throttle response.

With this in mind...I decided to get a rebuild kit and take it apart to clean it up. I had noticed that the boosters didn't flow nice and even like they should. In fact...one of them would drip real un-even as I revved the motor. I still don't think this would cause all the back-firing, and fouling of plugs, but since I bought the carb used, I thought it would be a good idea anyway. Get it right, and mark it off the list as a possible problem. Done.

Secondly...I headed over to my local speed shop and bought the curve kit for my MSD #8361 distributor. I put the lightest springs, and the smallest bushing in it to get the "steepest" curve I could. Mark problem two off the list. Done.

Then I started it...carb works MUCH better, but I still have the same problem with cylinders coming and going...backfiring, and just plain ole sucky performance. Now I'm thinking its something wrong with the MSD-6AL, (or more likely...my wiring). Has anyone out there had problems with their MSD-6 unit? I get the feeling its not grounded...or the motor's not grounded...or maybe its not getting a full 12volts? Anybody ever had mysterious cutting out and plug fouling with an MSD?

This is my first time with a MSD unit, and I know I got it hooked up correctly. But maybe its not getting grounded to the motor?

Any suggestions?

-CJ

[pro70z28]

Originally posted by 4speedfunk


maybe its not getting grounded to the motor?

Any suggestions?

-CJ

I would try running a ground wire directly from a bolt on the engine to a mounting bolt on the MSD box???

[The F.N.G.]

I don't mean to sound rude but have you tried using a voltmeter to locate the problem?

Abe

[junior]

i personally had the same problem ,however my problem ended up being a needle and seat not fully seating . i took it out gave it a couple of shots and bingo. problem solved.

[4speedfunk]

Abe....Yeah, the volt meter idea is great, except the problem comes and goes, and rarley does it sitting in the driveway. The misfire and stumbling happens when I take off down the road, under load. This makes it kind of difficult to read a volt meter, drive, and shift gears. Not to worry....I'll get it figured out. I'm going to rig up a "temporary ground loop" connecting the motor, frame, chassis, MSD, and battery all to one negative source...and see if that makes a difference. Update coming soon.
Thanks-CJ