Hi, PLEASE HELP!!
1989 POWER RAM 150 with 318.
Intermittent fuel delivery issue, have checked relay, power in and out, heading for fuel pump but I really don't think it's the pump but I've been wrong before lol. When it starts, crisp turnover, runs great. 5 minutes later, sluggish turnover, only run with start fluid or not at all. New battery and, at moment, starts and runs great. Afraid to drive it anywhere because worked fine the other day for a few hours and ended up being towed to shop. Codes 12,33,55 come up but seriously doubt a/c clutch. (No A/C).

 

How many miles? Did you check fuel pressure? Was the fuel filter ever changed? Sure it wasn't 32 or 34?

http://www.allpar.com/fix/80s-codes.html

 

new pump, filter, battery. Ran great for a week then has died again.

 

Also, now codes say 31,32,33,36

 

The sluggish crank is throwing me off, but have you tried swapping in a pickup coil? The fact that it starts and runs fine when it's cold but not after the motor has warmed up makes me think that the pickup coil is going bad, since they can be heat sensitive. And if it's weak it can produce enough spark to ignite alcohol, but not enough to reliably ignite gasoline.
I think a new pickup coil is usually around $10-15 at the local parts store, and it's an easy enough swap that it might be worth a try.