put on thinking cap I have been a mechanic for 7yrs supervisor 20 yrs have problem child 86 GMC?

Question

no pulse no fire cranks ok new pickup coil new HEI mod X3 new coil new ECM X3 first two junk yard last one out of box replaced ESC mod replaced coil to dist wires have pulled intire harness out and painstakingly checked all wires
one thing jumps out oil pressure switch X3 1st one wire one post 2nd two wire two post 3rd three wire one post could this be a problem? owner of truck shut off vehicle and as he was getting out foot caught wire under dash has not run buy itself since no pulse but still had fire could splash gas and run now it won't even do that what happened

Answer 1

The question is,, What wire did he pull,. Start theoretically, with the full wiring diagram, and most importantly, identify that wire. Your shot gunning right now, too many HEIs for no reason. Once the wire is identified, find out where it goes and what it does. It could have been pulled out of the wiring harness partially so you can't see it, or it could have shorted out the engine control module, or be shorted to another wire, or be open inside the coating or broken at the end connector.
But you must start theoretically and the starting point is that wire(s).

Answer 2

verify that the fuel pump is recieving power through the oil pressure switch . the wiring information is a little vague.

Answer 3

change the whole distributor then just basic direct wiring and see if it fires