I am hoping someone has run into the same problem as me.

I have a MSD 6AL box plugged into the stock ignition.

When the car is on the stock ignition, I can rev it all the way to 7142 rpm till I hit the fuel cut-off in the computer. Nice and smooth.

Now the problem:
This happens with the old 6AL box AND a brand new one that my friend has and let me borrow before he installs it on his car.

It revs smooth until I hit 6000 rpm. Then, Bam, Bam, Bam, Bam (6500, 4500, 5500, 4500) It's all over the place. It is not smooth like when it would hit a rev limiter. It is fast and hard.

One time it will bounce in the 3500 rpm range and another time in the 4500 rpm range. Never the same range. As soon as I plug the stock system back in, smooth as silk.

I have a new Opti, new 8.5mm Superconductor wires, new Autolite 104 plugs, a new MSD GM Balster coil (as of 10 minutes ago).

I have been on the phone with MSD 5 times. The wires are hooked up correctly, the fat wires go directly to the battery, the orange/black wires are 10 inches from the white wire, etc. I even took out the TR6-IX plugs because they said you could not run platinum or Iridium plugs with the MSD stuff.

Anyone ever run into this? If so, what was the fix?

 

Did you check the rev limiter settings on the MSD box. That box should have the ability to set 2 rev limiters, that might be the problem and is most likely why you can rev all the way to the stock rev limiter. I have run the Digital 6 MSD box for at least 3 years and never had a problem. I also had platinum plugs so that should not make a bit of differance. Another note, the MSD rev limiters kill the spark which is much easier on the engine as opposed to the stock limiter which cuts the fuel. You run a chance (albiet a small one) of detonation when you cut the fuel but not spark.

 

At the moment, there aren't any rpm pills on the box to set limits. The fuel cut-off limiter in the PCM is set at 7142 rpm. It's not hitting a limiter, it is WAY TOO HARSH.

After speaking with MSD again, apparently the MSD box is putting much more current through the stock opti. This is causing it to arc internally and cross/mis-fire erratically above 6000 rpm.

That's why they have created the MSD Billet Opti, which is good to 10,000 rpm.

It does not do it with the stock ignition, due to the lower output of the system.

Just my luck.