I'm considering ridding my problematic low pressure pump and high pressure pump setup on my 89 and just have the in-tank high pressure pump setup like later fords. What all do I need to do to accomplish this?

 

You'll need a way to bypass the old frame pump, which might or might not involve replacing most of the fuel line between the tank and the fuel rail, and a new gas tank with the larger opening for the larger pump.

You should be able to get what you need from one of the junkyards around here.

 

Wont I have to do some sort of different wiring if the stuff going to the tanks is only low pressure?

 

I don't think so - the low pressure pumps run on the same 12V that the high pressure pumps would. Subford might chime in here, but I don't think there are any wiring changes.

But you might want to think about why you have to make this switch - there are millions of trucks on the road using the low-pressure tank pumps and they seem to work reliably. I remember you had a thread on here about the problems you were having, but I don't remember what the outcome was.

 

The outcome was I was never able to put a gauge on the low pressure pump and the gauge I have as it is was 10 dollars so I'm unsure of the accuracy, but I can literally hear the gas flow through the high pressure pump at all times, and now the truck is even stalling completely but starts on the first try. Very occasionally I smell gas, like once a month. Most the time switching gears the truck drops a few hundred rpms but comes back up to 700. That's pretty much what I have to work with and it's irritating me because this is supposed the be my everyday driver and a reliable TRUCk which I know it can be.

It also has hesitation upon acceleration most always.

 

If I can't figure this out is there anyway I could meet you sometime and you could help ascertain the issue?

 

PM sent...

 

I found your old thread. https://www.ford-trucks.com/forums/8...questions.html

From what I read, it sounds like your fuel system is working fine. I really doubt it's the fuel pump, you are getting 35 PSI from the high pressure pump so I wouldn't worry about what the low pressure pump is doing.

So let's start with the basics - when was the last tune-up, including changing all filters and the PCV valve? What brand did you use? Have you pulled the codes?

 

Good thread, curious to that also, and might i also add im having the exact same issues on a 96 5.0L

 

If you change systems when you take the tanks off the newer truck cut the wiring ahead of the plug for both tanks and then splice the wires to your truck. Note some of the wire colors may not be the same. Then tape up the old plug to the frame pump.
Then rest of the fuel system changes are like what Andy said above.

That said if you think it is a fuel problem get a fuel pressure gauge and put it where you can see it as you drive. If it does its thing and you still have about 34+ PSI then it is not fuel delivery system related. If the hose is too short cut the gauge hose in the middle and splice in a hose so it will reach. This what most Ford dealers will do to rule out the fuel system.

On the 89 it sounds more like the TFI module on the distributor without reading the other Thread. If not that then the PIP sensor or wiring. Look close at the wiring under the relay sockets and the plug on the Ignition coil. Can also be the Ignition switch or the relays.

The 96 most likely the PIP sensor.