Finally Got the Gremlins Out - MSD Problems?

We wrapped up the summer series yesterday with the High Altitude Bracketnationals...

Finally Thursday night found the problem that was robbing me of over half a second and had us stumped since Pinks... turned out to be the MSD 6AL box was missing, especially at high revs but also mid rpm. The box was about 3 years old and has served me well those three years. I heard from another racer that's about it for their life expectancy... Anyone else have an opinion on how long you can expect the box to function?

Finding that problem was another matter... it felt like it was running out of gas and I had been having problems with fuel delivery so I spent a lot of time chasing fuel system issues... on the bright side, now that I wrapped the regulator in foam rubber insulation, the pressure has stayed steady.

Other problems we found/fixed trying to get to the root:
1 broken valve spring
1 leaky coil
1 high resistance coil wire
1 melted/cracked wire boot
1 glazed plug
1 loose wheel stud tearing up rear shoe (thank you Meineke! :mad: )

After correcting each of these made no difference in how she ran and scratching heads for awhile it became obvious the only thing left was that MSD box... so ran up to Checker's and got a new box and voila she was back to her old self :) Finally, about 9pm the night before testing for the big race...

All I can say is it was a great joy to drive down the strip when she runs and pulls and sounds just right... ending a month of frustration when she struggled just to get past 6000rpm.

I lost first round in both classes I was in but I still had a smile on my face cuz my baby was back...

Probably close to $2k in entry fees $5k in repairs and I think I made it to third round once this season... no checks, one trophy.

Now that the summer season is behind me, I'm ready to sweep the fall series :D

-Chris

I had almost the same problem with a Mallory HyFire VI-AL. That thing drove me nuts for quite a while. I went over everything several times.....
The thread is here

Thanks, Chuck... I read through your thread and it did sound like a similar problem... weird you only had problems with the alternator hooked up... I had problems both with and without the alternator (three wire). Funny how we spend so much time chasing fuel issues and the ignition box ends up the last thing you check... I'll have to move that higher on the list next time. I had always thought if the box went bad it would just quit altogether but it ran well enough and if you check it for spark it seems fine... chalk it up to experience or as the Germans like to say: "learning is hard" :LOL:

-Chris

For me everything was completely new (motor, ignition system, electrical, and fuel systems) and it ran fine for about 200~300 miles, then the problems began.
Talk about not knowing where to begin.....Everyone (not just here) said fuel, fuel, fuel.....live and learn.....it's all you can do :D

About 2 1/2 to 3 yrs seems to be the life of MSD 6AL boxes. I went thru 2 of them in the 6 yrs I ran my car. First box I started losing hi-rpm revs like my timing was off or I had hit the limiter. The second box started going in the mid to upper rpm range after the car had been run for awhile after start, an intermittent problem. Sent both boxes back to MSD and had them refurbished at about $80 ea...cheaper than buying new but I wasn't racing for points only open track road racing and street driving.

Thanks for adding your perspective G.R.... I'll see about sending my dead one back to get refurb... will be good to have a spare on hand for when it happens again.

-Chris

Veddy intedestingk!!

It amazes me how we always tend to jump right on the "carb/fuel system" wagon when we start experiencing problems like this. I have that tendency, and I should know better by now. That is not to say that it couldn't be fuel related, but quite often, an electrical disturbance in the ignition system is found to be the real culprit.

As to the failure of the "box", lasting through three years of heat and vibration doesen't seem unreasonable, nor does it's failure, all things considered. Electronic components are, by their very nature, less tolerant of errors in manufacturing than mechanical devices, and are more sesitive to their environment regardless of the efforts made to engineer them to not be so.

Something else that I picked out of this discussion is our continuing tendency to use mismatched components in system environments. In the old days, we'd get a dual points conversion for our distributor, of some brand or another, very often a Mallory "high voltage" coil, some Packard real copper plug wires, and whatever variety of cap and rotor we could lay hands on, and it all seemed to work just fine - but, it was all mechanical and basic electric stuff; sort of "clank" compared to todays engineered systems "ting". Today, a Mallory controller box is undoubtedly developed using all Mallory components, and made to work with them as a system. Even though the basic principles may be the same, an Accel, MSD, or other brand of system is developed using their own proprietary components, and mixing them is adding a lot of potential for error and failure due to mismatched engineering into the system. It does not take much to give a PC board the "willies".

One other thought, and I'll get of of my "old fart" soapbox: Have you considered moving your "box" from the engine compartment into the inside under the dash where it will not be subject to the relatively extreme heat? Electronics don't seem to like heat very much, and the might improve the longevity of the box.

Rrumbler very good point RE: moving the box out of the engine compartment... Some of my friends experienced problems running BB's in their Cobras using "brain boxes", be it MSD, Accel, or Mallory and their "ignition" problems went away when they moved their boxes into the cockpit and cushioned them for shock....another problem the boxes have.

Thanks Rrumbler for your perspective... I agree. My ignition system has been all MSD from dist to coil to box to timing control to 2-step to even the wires since I dumped the points 3 years ago (of course now I have an Accel coil since that was all I had available when I discovered the old one was leaking). I have considered moving all the ignition gizmos internal and mounting to a plate/board bolted to the passenger floor but I've been reluctant to do this as I do like to be able to take people for a ride... I'm sure I can find a happy medium. On the heat, that could be playing into this as I believe my underhood temps have increased since switching to the glass hood... Complicating matters I also had a real fuel system problem losing pressure as the regulator heats up that at least made it more difficult to come around to the ignition. I knew it had to be fuel or spark but it was a little of one and alot of the other.

-Chris