I bought this truck running, had a bad oil leak at back of engine- I believe was oil sending unit. It has two, one for gauge, one for dummy light. I changed them out. While I was at it I decided to install a re-manufactured distributor as the old one was in bad shape, has 180K miles. Now the thing wont' fire. 12 volts to the coil though. I'd read where they are sensitive to the oil sending units so I put the old one's back in and still nothing. What the heck? I had it on TDC before I removed it, even tried 180 degrees opposite and nothing. Now I'm lost for ideas considering the darn thing ran before replacing the distributor- does anybody have any ideas? Do you think I may have gotten a bad distributor? I can't try the old one as I turned it in as a core.
I know the '87 is a one-off as things changed in '88 & up.

 

See if it will run with the old one. The rebuilt might not be working.

 

Like I said, I don't have the old one as I turned it in for the core unfortunately. Thanks for the help anyway.

 

A few more things to check.

Your ASD relay; make sure it hasn't failed (this would kill the spark only on your truck.) If you have 12V to one side of the coil, that's probably not it.

The wiring to the ESC on your truck; make sure you didn't accidently leave some of it unplugged, or that the connector to the pickup in the distributor doesn't have a loose connection (either side, distributor or truck!)

Again, the wiring to the ESC; make sure that none of the connections went bad.

Pick up a copy of the factory service manual off Ebay (as I type this, they start at around $11 with free shipping; this may change by the time you read this, natch!)

RwP