I got a call to come down to help with the installation of an MSD distributor in a '67 (302) Mustang (I know, I know). Seams no matter what they did it just wouldn't run right. I got there and had them go back to the basics. Brought everything back to TDC, set the dist. at #1. Checked all the wires to see if they were wrong. All was good. Still wouldn't run right. Sounded like a few plug wires were crossed, or the dist. was off a tooth. So finally I had them put the old dist. back in. It ran perfectly. I'm thinking they got a Monday, or Friday dist. (factory defective). I haven't heard if they got hold of MSD yet, will let you know when I hear.
Thoughts anybody?

did you check the relucter gap.if its an older MSD dist. it could have some corosion inside.did the cap and rotor look good.

Most common is wires reversed--violet and green--the factory does it all the time. switch them and it should run fine--if backwards it adds timing to the tune of about 20 degrees or more.

this may be just already known imfo but on a ford the #1 is on the left side ,isnt it?

I had a new MSD dizzy that did similar a few years ago. Ended up being the existing coil would not work with the MSD dizzy.

The reluctor on MSD's is made from some odd metal that will RUST and CRUST like crazy--we always take new ones and WD40 the things, blow them off then put the cap on and go. BTW I have noticed in last year or two the MSD's overall quality has dropped like a rock--I think imported JUNK inside--The Crane units seem to be the better choice vs. the ole MSD Many Nascar teams have tossed all MSD stuff in favor of the Cranes saying they are Much more dependable

Ford cylinder numbering system:
Start at front passenger side as 1. then straight back 2,3,4.
Start at front of driver side 5, then straight back 6,7,8.

I'm having a similar hard time with a ford 400, seems like there's a hard miss that I can't get rid of. I suspect spark is jumping to the wrong terminal inside the cap.

R.

Couple questions. First, are you transferring the cap from the old to the MSD? Is it the original engine or a later 5.0? If it a later 5.0 out of a Lincoln they have a different firing order. My Ford friends found this out the hard way.