I'm converting from the fuel injection on an 88 w150 with the 318 to a carb. How do I make the fuel pump operate with everything unplugged?

 

The fuel pump is on a relay correct?
If so most times the computer will control the ground for the relay coil(pin 85), you should just be able to ground that to the chassis.
Without a schematic hard to be sure.

Dave

 

Yes it is on a relay. So do you think nothing I've unplugged from the fuel injection should matter, the pump should still run? Thanks for your help!

 

From the 95 service manual. This is the oldest manual i have with fuel injection. The circuits may not be named the same but will give you idea of how it is wired.

FUEL PUMP RELAY

Circuit A14 from fuse 8 in the Power Distribution
Center (PDC) supplies battery voltage to the contact

side of the fuel pump relay. Circuit F18 from fuse 9

in the fuse block supplies battery voltage to the coil
side of the fuel pump relay. The Powertrain Control
Module (PCM) provides the ground path for the coil
side of the relay on circuit K51. Circuit K51 connects
to cavity 51 of the PCM connector.
When the PCM grounds the fuel pump relay and
the contacts close, they connect circuits A14 and A61.

Circuit A61 supplies power to the fuel pump motor.

Dave

 

2001 manual show's same wiring method.
So if you ground the relay and turn the key on I would think it should run.

Dave

 

I wonder if you might need to look into a fuel pressure regulator, not positive on these trucks but most fuel injected vehicles need way more fuel pressure than carbed ones.

 

Your right he probably will.
Not sure does the system already have a return line?
I think the preasure for the throttle body fuel injection is 15 to 20 pounds isnt it?
Carb only needs at most 5 to 7 pounds.

Dave

 

my 87 only calls for 7 lbs MAX so its definitely gonna need a regulator

 

I put the fuel injection system back on, it was getting way to complicated for me. I found the EGR port in the intake manifold plugged when I took it off, cleaned it out, seems to run good now, however now when the engine is hot and I restart it, it revs up high and then comes down to normal idle speed. I can't find any vacuum leaks. Any thoughts? Thanks guys!