Hey guys, new to the forum but not new to how they work. Used to be in a jeep forum that helped me a ton! Hoping I'll get some good advice here. I'm a decent shade tree mechanic, my dad was a mechanic and I helped him all the time. I could install, set and adjust points by the time i was 12. In other words I'm pretty comfortable under a hood but I definitely don't know everything, hence why I'm here.
So, I have an 88 F250, 4x4, 7.5l(460), 5 speed truck and only 110k (6 digit odometer), has had a dually conversion and flatbed installed and best of all no rust. I'm having a crazy issue I've never seen on any vehicle I've ever owned. I had to replace the pick up coil so obviously I pulled the distributor, replaced the coil and reinstalled. Now, it's seated all the way, no issues with that but my rotor button was rubbing the distributor cap causing a misfire issue. I pulled the distributor again to make absolutely certain it is seated properly, put a new rotor button on and it's still doing it. It's a great old truck but this is driving me nuts. Any advice on what to check out do here?

Oh, the timing isn't the issue, I've confirmed all that.

Also secondary to this issue, based on cost is it with putting in an MSD distributor system?

 

I wouldn’t swap an MSD distro only due to recent stories read of poor quality these days. Where on the cap is it rubbing? Sides? Only one side? Top?

Have you removed the cap and watched it spin to see if anything looks off?

 

It's rubbing the top and thanks for the MSD input

 

Post a pic of the cap if you can. Is it rubbing where the points are or center where the coil point is?

 

It's rubbing at the coil point and a little past that. It's fuel injected with electronic ignition.

 

I haven’t replaced one before so I don’t have first hand experience, but it sounds like the shaft isn’t seated all the way.

 

Or the rotor is not pushed on there all the way, and the little tab is not down in the slot?
Post a picture of cap and rotor

 

It is in the slot, been kinda busy and haven't got apic. Work for myself so days are full.

 

Here is a Pic of the button, you can see it's rubbing all the way and you can also see according to the intake seat the distributor is fully seated.

 

Ouch! Its not the external shaft seated, it’s the internal shaft not being seated all the way in. The piece the rotor button sits on.

Can’t see from the picture, but upper Cretan the circled part in down in the hole all the way?

 

Sad thing is it is fully seated and has been. There's no slop in the shaft either.... fractional up/ down movement. Now I'm getting an egr sensor CEL

 

Hopefully someone else can come in with something! If it were me, I would be pulling it back out, apart and double checking everything.

 

I have!! Driving me nuts!!🤪 I've got the egr sensor pulled, cleaned it although it seemed fine. Is the egr valve supposed to move freely or only when running and builds pressure?

 

It’s moved by 3-5 psi of vacuum, so fairly easy.

Or do you mean you shake it up and down and it moves?

 

I meant should you be able to move it.... like push down and it moves.... seems sick in place to me. Truck is running but has no power in set load now