Driving along the truck just quits..getting no fuel.. couldn't hear the LP come on,Put on a new LP today, still the same thing. Any ideas.

 

Oil pressure switch powers the LP when engine is running-common failure point.

AC Delco ONLY for OPS replacement.

also google "OPS Relay Mod" and install for long term durability.

You also must have an air leak on the suction side of the system if the truck dies.
The IP can suck fuel from the tank with extra wear as a result from a non working LP,but only if it is a leak free system.

 

Yep I noticed the top off the fuel tank a little damp from fuel.. so any tricks to changing the ops,trying too see it.. but no luck on that.. should I remove the fuel filter bracket so it easier to get at.. and do I need a special tool..... thanks

 

Yes the OPS is under the intake some and much easier to locate if you remove the filter manager from it's mount,maybe entirely?

A special OPS socket is available at many auto parts stores but many folks with late model 6.5's use a plumbers basin wrench.

 

I got the basin Wrench, bending the small handle trying to get it out..are those things that tight in there or am I doing something wrong. Going too try putting a pipe wrench on the long handle and see if i can turn it that way.

 

I usually use a wrench that i heated up open end and bent....but still pain in *** to get at

 

usually not that tight-make sure you are going the proper direction.

 

I can get at it.. but won't turn, counter clockwise.

 

I didn't think the lift pump was dependent on the OPS in a 1998. Is that what you are working on?

You should not have to do the Lift pump relay upgrade on a 1998. You should have a relay already.

I would test for juice through the system to the lift pump.

Have you hot wired the lift pump to see if it would run?

You could have a problem wire or a bad relay.

If you have diagnosed the Oil Pressure Switch as bad then you may be going through extra work and expense for nothing.

First make sure the lift pump works when jumpered.

For an OEM style lift pump use only an AC Delco for a 1993. All the others do not have the same record for performance and reliability.

Either run wires directly to the lift pump or use the spade connector that is between the under hood fuse box and the firewall. Sometimes it can be hard to see, but it's down there.

I wouldn't do anything til you have determined the staus of your old lift pump and your new lift pump.

If the lift pump runs when jumpered - it is best to use a fused jumper - You can run down the road like that til you figure out your true problem. It is possible your problem lies on the other side of the lift pump

I always double check lift pumps after I have them off by trying to pump from container to container. New part does not necessarily equate to a good part.

 

Got her running.. it was the fuel pump relay, that didn't last to long.. went down the road she just dies again,not getting any fuel and don't hear the LP come on. The Fuel Pump Relay musta went again.