Ok I have a 1993 f150 with a engine from a 1995 f250 351W... All other kinks worked out but it surges unless you on the gas and the it even seems to skip.
KOEO pressure was 40psi KOER it dropped to 30 -32psi. KOEO pressure is right dead nuts in the middle of the scale but at the lowest part of the scale when running? Fuel pump? I'm changing the filter today or tomorrow. Any help would be great... Thanks
new parts
TPS
Map
Fuel pressure regulator
Injectors
plugs
wires
distributor (complete)

 

That part is correct.

Not sure what you mean by that. Fuel pressure should always increase towards the higher pressure under low vacuum and should never drop below the idle pressure.

 

When I was checking the fuel pressure the 40 psi was before I started it and and when I did start it during idle it was 30-32 psi and doesn't move much when I hit the gas.... just dont see why it would drop that much...
Is that a little clearer on what I was trying to say.... Sometimes my mind is faster then my hands... Thanks

 

Normal engine running pressure should be between 30-35psi for this motor so you are good there.

 

This thing is driving me nuts... Surging unless I'm on the accelerator... Just can't pin point the cause...

 

Any codes present?
Did you swap the motor or was this a project you inherited?

 

Old thread I know but kets see if someone answers. I have a 92 f150 nite with a 351w single tank. Does this truck have dual fuel pumps?

 

No it does not. Only one in-tank high pressure fuel pump on your truck.

 

I didnt think so, thanks for the reply

 

Sorry wrong forum/thread! Scrolled to the bottom of the page and didn't realize it was showing a different thread.

 

so, would this same set up from the 92 with a single tank work on my 87 with a dual tank? Having issues with the front tank. If I deleted the selector pump on thr frame and and put a high pressure pump like the 92 in the rear tank and one in the front tank would it work? Would just need to figure out how to select from one tank to the other.

 

I have conflicting information that a 1990 and later Fuel Delivery Module (FDM) will fit the earlier ~1985-89 F-series gas engine EFI trucks. If it does that would make the swap easier I suppose. The other concern is if the fuel lines from the tanks that are using a low pressure pump are rated for the higher pressure.

The tank selector switch controls which tank/FDM is selected by supplying power and the connections for the fuel sending units. There is no other valve or switch required to make it work on a dual tank truck on the 1990 and later gas engine F-series trucks.

 

Thanks for the reply, the fuel lines have been redone and should be fine for the higher pressure. The selector switch/pump is where my problem is. It works off of pressure and when both tanks are full. The pump will start filling the other tank and overfill it causing it to leak. Another problem is, when the front tank is selected it starts to buck like it has low pressure. The pumps have been changed multiple times and even switched from front to rear. Still same problem, that's how I figured it is the selector pump causing the problem. It works just fine on the rear tank only. As long as I don't switch tanks its been running fine.