Ok. I'm at my wits end with this thing. Chasing a gremlin. I put in new distributor complete w/ pickup and module, cap, plugs, wires. It won't show any codes. Has dual tanks and all pumps working fine with good pressure. New pressure regulator also. There is an intermittant miss that seems to juggle between different cylinders, not consistant. I'm getting spark to all cyls, but not getting advance. I inspected wiring and it has this peculiar extra wire going from the brown wire from eec relay and fuel pump relay straight to ground. The previous owner must have done this mod, and when I try to disconnect it it kills the relays. According to the schematics this wire should not be there. Doesn't the eec on pin 22 supposed to be the ground? Here is a link to the schematic Ford Wiring Harness F150 Schematic F250 Diagram Van With Diagrams - WIRING DIAGRAM

 

That diagram you have is lousy(I have used it before). Here's a link to a better diagram. It's for a 86 but should be good for your truck.

1986 EVTM - ???Gary's Garagemahal

 

"but not getting advance"

Are you familiar with the SPOUT Connector?

If this is removed, or there is a break in the wire, your spark will not advance.


How are you checking codes ?

 

If the intermittent miss was occurring both before and after the dist., cap & wire, my comment here would not very likely apply. If you have the miss only after the change, you may want to be certain the wires to #7 and #8 cylinders are separated. These cylinders fire in succession and it has been documented that the spark will jump between these two.There was a TSB on this, but for some reason, it was only issued for Broncos. It fixed the miss in my '86 F150 5.0 EFI.