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MSD unit dies

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hondo402000

hondo402000

Darth Vader
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went to crank the TR6 yesterday, crank,crank, crank, wont start, pull the spare plug out of the trunk, stick it in a plug wire turn over the engine, no spark, pull the coil wire and check it there, no spark, find the MSD manual, says hold coil wire to ground, find white wire going to distributor, turn on Ig switch and tough white wire to ground and pull away and you should get a spark, no spark, manual says" send back for repair" purchased a new unit 250.00, will install today, if old one is bad I will send off to be repaired and have a spare,
 
...I ain't sayin' NOTHIN'.... /bcforum/images/%%GRAEMLIN_URL%%/whistle.gif
 
They're great when they work. When they don't you're stuck. Having a spare on-board would be the only sane way to proceed, IMO.
 
Well just got the new one on and she fired right up! unfortunately the were not identical units, original was a 6A and the new one a 6AL so the mounting holes were a little different, ug... I might have helped kill the first one, I didnt install the diode for the runon problem and I had to pull the coil wire to get the engine to quit a couple of times till I figured out the problem, so that might have help kill the unit, boy that thing will shock the crap out of you
 
We actually mounted two boxes in the race car next to each other and had a toggle switch for all the low tension wiring.

Can't tell you how many went poof.
 
Hondo,

The MSD can be by-passed easily. The instal instructions even show how to swap 3 wires to go back to normal ignition.

This is the reason I never went to Petronix, I hate getting stuck but even the Petronix can be swaped easily by carrying a spare breaker plate w/points installed in the trunk.
 
DrEntropy said:
...I ain't sayin' NOTHIN'.... /bcforum/images/%%GRAEMLIN_URL%%/whistle.gif
Click to expand...

Yeah, that's why almost everyone that I know carries the guts of their stock dizzy in the truck /bcforum/images/%%GRAEMLIN_URL%%/rolleyes.gif So I wouldn't call the old guard THAT reliable.

I just don't understand all this animosity towards the electronic ignitions. IMO they're superior in almost every way to the points they replace.
 
As I see it, the MSD is a racing part; so like most racing parts, it needs to be replaced periodically. Certainly that's been my experience, as I've had at least 4 different MSD boxes fail in one way or the other.

I think the most amusing (in retrospect) was the 6A box I put on the Chevy. On some cold mornings, the engine would start just fine and run for about 5 minutes, then simply die like the key was turned off. Always at idle, too, so it would always catch me at a stop light (or sign). Dead as a doornail for anywhere from 10 seconds to about 5 minutes; then the engine would start and run just fine the rest of the day! (Even after sitting for several hours.) Took me a long time to be convinced it was the MSD box at fault; but after I finally changed it, the problem disappeared and never came back.
 
I don't know Shannon,

My professionally installed Petronix, in my professionally
rebuilt dizzy, crapped out with less than 200 miles on it.
No, I didn't leave the key on.

I have had no problems with the cheapo points and condenser
installed by That Canada Guy, international mechanic.

I carry three sets of spare points/condensers/coils/plugs
but wouldn't waste my money again on a Petronix.

Just my opinion.

d
 
I had pertronix in the wife's '68 mustang for over 10 years with no problems?!
 
While I agree the MSD units are far better at timing the output properly and deliver a good whack, I just feel it is too much expense when having a spare set of points 'n condensor inna glovebox is what'll get ya home, for a couple o' fins. These old tractor engines aren't that fussy anyway. Suck-squish-bang-pffft.... you're underway. $200 vs. $20 for makin' the bang part happen seems excessive to me. :shrug:

That said, I've fitted PLENTY of the black box gizmos to OPC's (Other People's Cars). And replaced my share of failed ones, too.
 
Doc, you have obviously had my chili before...

"Suck-squish-bang-pffft...."

LOL!
 
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