I am getting conflicting info.

I am putting on a NAPA water seperator/filter and a Holley "RED" fuel pump.

I say put the filter on first then the pump as far back as possible and let the pump pull through the filter and push the fuel to the motor.

Also is there any need to have the filter and pump below the fill on the tank, below the tank or anything? I want them tucked up out of the way.

AND, what is the danger of letting the electric pump feed the engine mounted lift pump? Blown out diaphram? Too much pressure? Fuel in oil if pump goes?

FINALLY, what is the bio diesel safe fuel line called again? I'm too lazy to look back for it.

I'm trying to set a record for most questions on one thread!

 

To protect the fuel pump, put the filter prior to the fuel pump. The holley 801 (red) is internally set to 7psi so that should not cause a problem.

 

You can get a smaller in line fuel filter and place that before the pump. I've seen many OEM electric fuel pump vehicles were set up with an in line filter----fuel pump-------main fuel filter in or close to the engine bay----then to the engine fuel system. This means the electric pump can be very close to you tank. Ideally, right after the selector valve.

I've heard of guys that keep the OEM lift pump and have problems like what you listed but surging can also happen.

I think the fuel line material you are looking for is called "Viton". They can rebuild your injector pump with seals made of that stuff too.

 

I put my filter after selector valve then the fuel pump and no manual pump (just carry a extra chepo pump with you) do not use the 2 together (manual / eletric) you will blow out the manual I tried it used the electric only to prime the manual and still blew it out...

 

Mine runs through a electric plunger type pump under the cab (puts out about 3-4psi) about where my seat is, then it runs through a small clear $3 plastic inline filter (so I can see whats in it and I keep a spare) then it goes to the mecanical lift pump (I have had no trouble with the lift pump) then goes to the water fuel water seperator/filter then to the injection pump. I have had this setup for over 26,000 miles with no trouble. If I need to purge the system, I just turn the key on for a munite or 2 letting the electric pump work then it starts off in under 10 seconds of cranking. Works great. My electric pump is tied in with the ignition so it runs when the key is on. When I got this truck, this setup was on it so I just contunied to use it. The pump and bracket look old and original (not factory though) and have close to 190,000 miles on them. I have an aux tank with lots of rust and sand so The clear plastice filter works great to see what Im getting out. I have no loss of power with it on even while towing. ( know because I have bypassed it when my fuel filter light came on and didn't have a spare) Some of this may not apply to yours but figured Id just share what I have hooked up.

Just to add, The Fuel filter light will tell you when any other filter/restriction is present in the system, not just the factory one.

 

I have a clear plastic in-line filter in front of the fuel pump, then the fuel pump then the water seperator then the factory filter/seperator. It doesn't look like I ever get all of the air out of the in-line filter even while it's running or just running the fuel pump to purge everything.

I haven't driven it yet with this set-up as the air in the inline filter makes me nervous. Just ran it in the driveway.

 

With an electric pump, I would get rid of the mechanical pump.

If the diaphram in the mechanical springs a leak, the fuel will go in the oil pan.
You first indication of a problem is going to be either oil pressure drops to 0 or oil/fuel mix blowing out of the dipstick tube onto the exhaust manifold.

Bottom line, bearings are probably toast.

Fuel filter, after the electric pump.
That way you can use the electric pump to prime the filter.

Look at a Holley Red pump.
100 gallons per hour.
So if you have a 20 gallon tank, the fuel in that tank will be filtered 5 times every hour.

Filter before the pump, a slight restriction in the pre pump filter and you are sucking air at any place even slightly questionable.
Part of the problem with the 86 and earlier water seperator sucking air was because it was before the lift pump.

 

Also, do the "O" rings or seals, or whatever, in the little elbow conectors on the fuel tank selector ever let air in.? They seem to be kind of hokey. I put new clips on the lines but they feel kinda "loose" for lack of a better term.

 

Mine are original 1986 model O rings.

Yes, the tanks have been removed and reinstalled several times.

 

2 reasons I put my clear filter before the pump...
1) warrenty requires it.
2) I run wmo so want to make sure any gunk get caught before my pump ...
my filter is only 2-3 inches after seletor valve and then the pump is 2-3 inches from it (the length of the rubber hose that comes with the fram filters at wal-mart)
my truck has no water seperator... and with my wmo set up I can check if filter is getting clogged up... it much cheeper to buy a 2 dollar filter than the 14 wix filter...