Truck Repair: No spark from Distributor, oil pressure switch, power weather

Question
1987 Gmc V3500, Crew cab, 1 ton, dually,454TBI, 4spd manual,4wd.  I have Spark in from the Remote coil but not coming out of "New" distributor (everything tests out there) to plugs. I have been directed to the knock sensor but cannot find it, everything shows it being in front of the starter just above the oil pan line. I also have a wire loose that I believe (If I read Haynes diagram correctly) is the Fuel pump oil press relay "a single orange wire", I dont know where the relay is located to plug it in. Injectors are spraying fuel while cranking engine. Coil is sending spark to distributor but distributor is not sending spark to plugs. I had to wait for a couple of days for you to be available, but after reading your level of experience figured it was worth it. Thank you for your time on this Forum and Thank you in advance for Helping Me .

Answer
Hello Charles,
It is NOT going to be the knock sensor, which should be screwed into the side of the block, just above the edge of the oil pan, just in front of the starter.
The knock sensor retards the timing, so if you want to unplug it, go ahead, but if it is retarding it, the sensor is good, so don't replace it.
I would look inside that distributor, and make sure the rotor is turning first. And then, make sure it is properly timed.

The fuel pump relay should be on the passengers side of the firewall.
But is isn't a fuel pump oil pressure relay.
The way it works, is, there is a relay for the fuel pump, but there is ALSO an oil pressure switch.
The relay closes during cranking, and should supply power to the fuel pump as long as there is a crank signal.\
But as soon as oil pressure builds to 4PSI, that switch closes, and also supplies power to the fuel pump, and continues to power the pump till the oil pressure drops below 4PSI. That switch is directly powered by a fusible link, and has power weather the ignition switch is on or off.
That orange wire probably does go to a connector at the relay, but has no bearing on the relay. Just uses the connector.

454 has hot fuel handling, so in some conditions, the fuel pump will run for much more than the normal two to three seconds when the key is turned on.

So back to the spark,
Make sure the rotor is turning.
Make sure the distributor cap center connector has continuity.
Test the coil wire.
Make sure the distributor isn't 180 degrees out of time.

Van