MSD's got me whipped!

[hound dog]

Well, let's see, where to begin. Had the cobra down at Carolina Motorsports Park a couple of weeks ago for the big get together sponsored by Whitby and CobraEarl. Had a ball, came home and took the cobra off the trailer, parked it in the garage. A week later I got in to drive around a little bit and it would not start. A little bit of checking and I found out there was no spark. I have checked all of the leads going to the MSD 6AL and everything is fine. I've performed the MSD diagnostic by shorting the lead going to the distributor and checking for a spark from the coil to ground, perfect! Still no fire to the plugs. It appears that the box and coil are in good working order (coil fires when doing the diagnostic but not when cranking). So I think I may have a problem with the MSD distributor such as the electronic module inside. I have a gap between the module and the vanes on the distributor shaft of .032 which seems a bit on the wide side. I think everything is in good working order except something is not telling the ignition system to fire. Does anyone have any ideas on what the problem might be or where to look next? Grounded in Carolina!
h dog

[Steve R]

Hound Dog,
Sounds like you are on top of the situation. Make sure the terminals inside the male and female sides of the distributer connector are not pushed back, or are being pushed back when you connect it. If they are O.K., it looks like you will need to replace the module in the distributor. Oh, don't forget to make sure the distributor shaft turns when you crank the engine.
One more thing you could look at. Perform the "shorting" test while your buddy cranks the engine. If you are still getting good spark, then you ignition switch is most likely not causing the problem.
Steven

[NROTOXIN]

h dog,
If you have spark by taking the distributor out of the loop i.e. jumpering it out then it is your distrib. Did you measure the module's resistance? Should be 400 to 1300 ohms....remember the distributor is also a triggering device (tells the ignition to fire). As Steve said make sure the thing rotates.

curtis

[decooney]

houng dog,
the pick up coils in the MSD's do go bad. A friend had an intermittent problem that nobody could solve... turns out the resistance was off on the pick up coil in the distributor. Pulled it out, broke open the pickup coil to see, and the wires were not connected very well and frayed... Yep, that was it!

Bought a new one from Summit for $17 I believe. Popped it in and he had no problems since. I carry a spare now myself just in case. They always seem to get rusty from the moisture in the cap too.

[hound dog]

Thanks, guys! Yep, the distributor is turning and hasn't skipped a tooth on the drive gear. Checking the resistance in the distributor it starts at about 500 and steadily climbs to over 1100 over a period of several minutes. I'll call MSD this morning to find out if this is normal.
h dog

[Clois Harlan]

Hound Dog,

I just went through the exact same thing...Found the problem to be in the distributor. My magnetic pickup was bad. Cheapest part to replace about $30.00 (unfortunately I had already replace my coil and MSD 6AL box.

Now I have a new system plus some back up parts.

Clois

[hound dog]

The new magnetic pickup arrived today and I installed it this evening. Engine fired right up! That's my baby! Sure am glad I didn't have to find it from the other end like Clois did
h dog

[REDSC400]

Well, I recently had the same problem. Check the MSD and that was not it. Checked the coil it was putting out via the MSD test. The sensor unit inside the distributor, (Mine is a Mallory Unilite) was bad. Darned expensive little item. I think I will always have a spare around to boot.

This things are the most delicate in the chain of the charge. Any power spike or sever variance will indeed play havoc with them. SOmetimes a jump starting or battery charger will whack them as well. I think you can somewhat protect the unit with a power ballast resistor or one step above that is a power conditioner. How effective those are I do not know.

I think a spare coil, rotor, and distributor sensor switch, fanbelt and one or more spark plugs are pretty much (Must haves) in the way of spares.

Hope you find the problem.

[Jack21]

MSD oughtto replace these things for you free of charge. Anyone ask 'em?

Thanks for the tip on keeping a spare though.

[REDSC400]

Jack,
In my case, the MSD unit was not broken, it was the Mallory photo-sensor inside the distributor. My MSD unit was fine as was Hound Dogs. His MSD sensor inside the distributor was also the culpret. These things have a 90 day waranttee I think. Mine had been running for 10 years until it blew.

Originally posted by Jack21


MSD oughtto replace these things for you free of charge. Anyone ask 'em?

Thanks for the tip on keeping a spare though.

[Ron61]

More of a question than any answer. Do all of the MSDs now have the optic type sensor ? I use a Jacobs and in their papers thay say either use points or a magnetic pickup. I know one person that went through four of the optic sensors before he bought a magnetic one and has never had a problem since. I do use the Mallory distributor by the way and I have had mine in since 1998 and never had a problem. Just wondering.

Ron

[Gary Morris]

When I saw this thread I told myself I know what it is as I went
through the same thing and almost never figured it out with 6
helpers. Club Cobra is great. Glad you got it fixed.

Gary
ERA #291

[hound dog]

The magnetic pickup will definately be a spare item at around $20.00. I still can't figure out whats to go bad on a magnet though
h dog