This was the reply I received from MSD regarding my 6AL Ignition throwing funny codes!

Dear Sir;

You'll need to install PN 8910. This is an adapter that will make sure the computer knows the MSD is installed.

Thank You,
MSD Tech

Do any of you guys who have MSD's, have this part??

Why doesn't it come with the kit?

How much are they? ? ?

 

Part #8910 is the Tach Adapter. It's suppose to correct the operation of the tach or fuel injection systems that don't work directly off the tach output terminal of the MSd unit.

I have to tell you though, the MSD 6A is notorious for causing eratic tach readings and MSD recommends part 8910 to fix it. However, they also say you're suppose to install it by bypassing the factry tach filter. NO ONE has EVER found the mysterious GM tach filter on our cars.

 

That might be the infamous "tach filter" they use as their canned answer. Did you look up that part number on their site? There's nothing in the computer that cares whether you have an MSD ignition or not.

 

Yes it is the tach filter! I ordered one tonight in hopes that even if it doesn't cure the code 43, 45 problem it might help with the bouncing tach during acceleration. Do you know if it at least works for that?? Does your cars have the bouncing tach action? Is this part ?

 

I have a 6AL on my 91 with replacement blaster coil and wiring harness. No codes, no bouncing tach, just good clean ignition with a 5K cutoff.

Barry F

 

I have no bouncing tach problems, but I went with the Accel 300+ digital ignition over the MSD.

 

It'll cure the bouncing tach problem for sure, but the codes issue... I dont think its going to do squat for you there. With it disconnected, do you still get the codes? Is it hooked up properly?

 

It is hooked up properly, I am going to un-hook it tonight to see for sure if it the culprit. Thanks for the input guys.