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MSD 6AL Issues

Nick2317

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Just wondering if anyone has ever had issues with the 6al MSD ignition box? My car started running like crap barely idles and runs rough and will stall ....We changed plugs,checked compression 150+ per cylinder,checked cap and rotor and checked all the plugs for damage etc everything was good so now we are down to MSD or a cam lobe gone which I don't think it is ....Anyone have any input
 
Nick,
I'll ask the obvious....have you substituted the MSD box with a known good unit? Have you checked the pickup coil connections for continuity or shorts? Or substituted the coil? And of course is everything that is supposed to be grounded is securely grounded. Just my opinion of course.
Bob Renton
 
Nick,
I'll ask the obvious....have you substituted the MSD box with a known good unit? Have you checked the pickup coil connections for continuity or shorts? Or substituted the coil? And of course is everything that is supposed to be grounded is securely grounded. Just my opinion of course.
Bob Renton

checked the coil and all connections are good ....like I said last 2 options were the msd box or a cam lobe
 
Is you box grounded directly to the battery. I had the same trouble on the Charger I bought. Box was grounded to frame. We moved the ground to the battery as per MSD recommendation and it runs sooo much better.
 
Nick,
How much does the MSD box for your application cost? Perhaps you should consider buying a spare unit as a backup? In my opinion, a cam failure is possible but highly unlikely. A lobe failure is generally a gradual occurance. Most lobe failures occur during or slightly after initial start up but can occur later but generally occur over time. Are you sure or have you checked for rocker arm operation? Possibly a punched out rocker arm or a bent push rod .... never hurts to pull the valve covers and look....just your time. One more time...did you check the distributor's pickup coil/ trigger coil for continuity? Just my opinion of course.
Bob Renton
 
Check the polarity of the distributor pickup wires, there's a blurb about it in the instructions. If the polarity is somehow switched it can cause a 40 degree change in the timing which would obviously be a problem.

This happened to me several years ago where everything was OK then the car wouldn't start. I was doing some other things at the time so I'm not sure how it happened but as soon as I switched the wires the car started on the first try and ran great.

Just a thought.
 
Had the same thing as rmchgr happen... twice. Switched the polarity and it ran again. Glad to know I am not the only one to have that happen. But, I never figured out how to prevent it from happening again.

....I probably need to go out and switch the polarity again..Lol
 
Gentlemen,
IF reversing the polarity of the pick up/trigger coil in the distributor needs reversed in order to operate correctly (again) how did it operate correctly in the first place? OR because of some MSD's idiosyncratic issues, should this polarity issue be a preventative maintenance point....every _______ miles (fill in the blank to suit). All the trigger coil does is generate a square wave pulse, which, when applied to the MSD circuitry, produces the desired output. I'm not debating that this issue occurs it just does not make sense .... electronic devices, especially solid state devices seldom fix themselves. From an engineering standpoint I would want to know the how and why's. To my knowledge, this phenomenon has never occurred with a points style (single or dual point distributor) ignition system......or MSD strikes again...... just my opinion of course.
Bob Renton
 
it ran fine til 2 weeks ago then this started ....the MSd has been on the car for 20 years or so ......its not wired wrong or anything
 
This isn't a easy thing to explain....but a typical problem with msd is a magnetic pickup polarity issue which causes the timing to be off 20 to 30 degrees and it will run rough or just crank and not start at all(what I have experienced). Many people initially just have the two wires reversed and there timing is off...they switch the wires and the timing is where its suppose to be. The newer msd boxes are polarity protected so the box is ok..the signal for the timing is being read wrong causing it to fire wrong. But the problems don't stop with just simple wires hooked up backwards scenario. It can be just fine...timing and polarity is right(for years) and all of a sudden the magnetic pickup sends a signal that the msd reads wrong making your timing off. Some say that a magnet is cracked sending a false signal. Others say something can happen causing the polarity to switch in the distributor. Another anomaly has to do with not enough clearance on the pickup and to strong of a signal at high rpms.

I just find it annoying when one of my cars doesn't start because the 6AL isn't smart enough to figure out a signal from a incredibly simple distributor that the old mopar box with nothing digital inside it...read fine.
 
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I recently repaired an MSD distributor in a Ford (they use the same magnetic pickup as MoPar) - and it was a cracked magnet. It is also worthwhile checking the reluctor gap (rotor trigger tips to magnetic pickup) - using a non-ferrous feeler gauge - Brass or Plastic.
Checking the voltage output of the distributor is really easy, and that is where I would start in this case.

Below is some video of my experience....





This car had not run for a year or more, and it has a disabling circuit in the ignition...owner was at work when we did the start-up....hence the initial hiccups while trying to start it.



Car hauls *** now....and starts every time.

:thumbsup:
 
I recently repaired an MSD distributor in a Ford (they use the same magnetic pickup as MoPar) - and it was a cracked magnet. It is also worthwhile checking the reluctor gap (rotor trigger tips to magnetic pickup) - using a non-ferrous feeler gauge - Brass or Plastic.
Checking the voltage output of the distributor s really easy, and that is where I would start in this case.

Below is some video of my experience....





This car had not run for a year or more, and it has a disabling circuit in the ignition...owner was at work when we did the start-up....hence the initial hiccups while trying to start it.



Car hauls *** now....and starts every time.

Just my opinion.....be fortunate that these two blokes don't do brain surgery....it appears that they can't find their asses with both hands....the old fumble and stumble method of troubleshooting prevails. Perhaps things are done differently in New Zealand.....
Bob Renton
:thumbsup:
 
Last edited by a moderator:
I recently repaired an MSD distributor in a Ford (they use the same magnetic pickup as MoPar) - and it was a cracked magnet. It is also worthwhile checking the reluctor gap (rotor trigger tips to magnetic pickup) - using a non-ferrous feeler gauge - Brass or Plastic.
Checking the voltage output of the distributor s really easy, and that is where I would start in this case.

Below is some video of my experience....





This car had not run for a year or more, and it has a disabling circuit in the ignition...owner was at work when we did the start-up....hence the initial hiccups while trying to start it.



Car hauls *** now....and starts every time.
:thumbsup:

Nice work. By the way have you ever considered doing any hand modeling..
 
My car started running like crap barely idles and runs rough and will stall ....

I know you're asking about the ignition but with those symptoms, did you check for a vacuum leak?
 
I recently repaired an MSD distributor in a Ford (they use the same magnetic pickup as MoPar) - and it was a cracked magnet. It is also worthwhile checking the reluctor gap (rotor trigger tips to magnetic pickup) - using a non-ferrous feeler gauge - Brass or Plastic.
Checking the voltage output of the distributor is really easy, and that is where I would start in this case.

Below is some video of my experience....





This car had not run for a year or more, and it has a disabling circuit in the ignition...owner was at work when we did the start-up....hence the initial hiccups while trying to start it.



Car hauls *** now....and starts every time.

:thumbsup:

Roger

Thanks for posting the informative videos and information. It is wonderful to have members as yourself that take the time to actually provide beneficial information for all viewing to learn from. I just cannot imagine why someone is bagging on another for that....Really, tells the character of that douchebag......

Carry on Gentleman.....
 
Roger

Thanks for posting the informative videos and information. It is wonderful to have members as yourself that take the time to actually provide beneficial information for all viewing to learn from. I just cannot imagine why someone is bagging on another for that....Really, tells the character of that douchebag......

Carry on Gentleman.....
Thanks Justin. I do try to help where I can. :thumbsup:

Maybe when I finish shaving the hair off my palms, I can post some hand pictures. :D
 
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