MSD Ignition question… starting to question my sanity.

Turk919

Turk919

Well-Known Member
Joined
Feb 19, 2019
Location
Garner NC
So, I consider myself a pretty stupid fella but this is making me feel really stupid. I feel like I need a sounding board or someone to say “yeah mine did that and it was XYZ” so I’ll feel a bit better.


My 84 Grand Wagoneer randomly loses spark when it’s up to temperature and normally when off the throttle or coming to a stop. I know it’s actually losing spark since I’ll hook a test light to the coil and after it sits for a few, it’ll regain it and fire back up, only to stall again a few minutes later.

I went through every connection on it earlier and moved a few wires around to make sure connections were good but she still stalled, albeit after a longer amount of time running (35 minutes or so)

Box is hooked to the battery, pickups are clear of the coil power wires, box should be getting 12v of power when the ignition is in the crank/run position. I’ve done the spark test with a paper clip to confirm what it should look like when working, but I need the bastard to actually cut off when warm so I can do the procedure and check for spark. If I can’t get spark when it’s acting up, I’m going to check for voltage at the ignition trigger wire, and if it has it, I’m going to assume the MSD box is getting hot or something internally and losing the spark signal.

Is there anything else I can check? Or anyone just had a MSD box go bad? I’ve tried a new coil, smacked the box a few times, jiggled wires, the ignition switch, etc. Nothing I have done as of yet has made it cut off unless it wants to.

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I am pretty sure I have one of those -6 boxes in my parts pile. It'll be a couple of days, but I can check, and if I find it, you can swap/test with it. If you don't hear from me by Thursday evening or so, drop me a PM and remind me.
 
So, I finally got a chance this evening to test the box out, she bad. It’ll lose fire for 5 or so minutes till the box cools off and it’ll light back off.

@kaiser715, if you have one and would be interested in selling it, I’d be interested. That issue has kept this Jeep in the garage off and on for a year or so.
 
orange150 said:
You can send it back to MSD and they’ll fix it. I think it was free? I can’t remember anymore, it’s been years.
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I called them earlier this week and they said these potted boxes are not serviceable, all they will do is run it for a while and smack it with a hammer.

Weighing the options of replacing the box, or buying a DUI and removing all of the MSD gear, just depends on what I can find and the price, I can always test a MSD on the side of the road with a paper clip.
 
Get rid of the msd stuff. They do make some good stuff but their non high end ignition stuff is pretty failure prone, distributors included
 
Turk919 said:
I called them earlier this week and they said these potted boxes are not serviceable, all they will do is run it for a while and smack it with a hammer.

Weighing the options of replacing the box, or buying a DUI and removing all of the MSD gear, just depends on what I can find and the price, I can always test a MSD on the side of the road with a paper clip.
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Is the box you're running analog or digital? If it isn't digital, switch to the Digital 6AL I've heard the analog boxes were junk but the digital got much better. I've been running a used one on my 22re for over a year now and have had no issues.
 
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