Ok so one of my 6A boxes it starting to give me issues. I thought it was the wiring so I re-wired it. The problem remained so I removed the box and the problem went away. Along with some of the low rpm power.

The issue is that it is acting like the rev limiter is kicking in at random intervals. Not always. I will be driving along and its like someone dropped in a 2000rpm chip. All of a sudden it wont rev over 2000 then just as quick as it started it will go away and be perfect. It does not happen at any specific point or temperature. Just totally at random. I have even removed the rev limit chips all together and tried that as well as putting in a 7000rpm chip. (I know the motor won't rev that high that's why I put in a high rpm chip)


Anyone ever had this problem come up and then find a way to fix it.

I know I can go online and buy a newer box or even a replacement box of the same kind cheap enough, but I was hoping to get a little more life out of this one.

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85GT 5spd ,93 Eldorado 4.9 Dual O2 Custom Chip, Archie Clutch. Custom Exhaust. MSD Everything 245/50/16's Not Your Average 4.9 Capt Fiero Com --- My Over View Cadero Pics Yellow 88GT 5spd Stock.

Unfortunately, they have a pretty high failure rate and I don't know of anyone that can actually repair one outside of MSD... and I don't know if they bother fixing them anymore or just replace them. Most racers carry a spare, nascar types have switch boxes in car for when they fail so they have redundant ignition systems.. flick a switch when it acts up and your on your backup ignition system.

I assume you have no warrenty of any kind on that thing? If so, it might be time to open it up and look for signs of trouble. I'd be willing to give it a look if you feel like dropping by here.

Nope no warranty, been running this box for over 5 years. Been in 2 revisions of my assorted 6's and now in the V8. Jax if I can't sort it out, I will drop it by for you to take a look at. I just sent a message out to the MSD techs asking if they know of a common failure point and could point me in the right direction. It is amazingly simple inside the box, I have had it open in the past when I needed to change it to run on the V8 after being on the 6. It has less parts than a 1960's transistor radio.

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85GT 5spd ,93 Eldorado 4.9 Dual O2 Custom Chip, Archie Clutch. Custom Exhaust. MSD Everything 245/50/16's Not Your Average 4.9 Capt Fiero Com --- My Over View Cadero Pics Yellow 88GT 5spd Stock.

MSD will repair your unit for 35 bucks. Give them a call.

http://www.dainst.com/info/circuits/msd6a_02.pdf

this guy reverse engineered it and created a bit of a schematic of the 6a.

This might help for repairs. it also could be a cold solder joint in there, think of all the vibration that could have caused one bad solder point to finally go.

Well I popped it apart and took some snap shots.

There were a couple of points, that had me going hmmmmm. However none of them really looked like they could have been the root of the problem. The insulation was scuffed a bit on a couple of wires but not broken through. There is one wire that looks like it has managed to glue itself to the case and one copper wire that seems to be out of place. I actually noticed more looking at the pics then I did when I was looking it at in person.

There is a gallery of pics at http://captfiero.com/msd6alguts

Here are some pics that kinda stood out for me.

When mine went, I took it out but left the high output coil in, and I really did not notice any performance loss except that the MSD 6A fired better at a cold start. I'm not at all convinced it is worth the $$ on our engines. I do think it might make some difference if the engine was turning 10,000 rpm though.

Arn