Filter housing

[Jcris]

After long last the 86 bullnose is running. The latest test was no fuel pressure. Turns out there’s a black plastic fuel filter bolted on the frame that was clogged. There are 2 return and 2 pressure hoses going through this filter. There are what appear to be check valves in this housing that were rusted closed. I’m guessing those are there to prevent fuel surge but I’m not sure. I removed the spring and rubber diaphragm of both to clear the clogs. Is it a mistake to leave them out?

I suspect any related issues won’t occur until rpms are increased but again I’m not sure. These do not look serviceable. Other than replacing the entire filter housing. What do you folks think? Also, is there a link to look up tuning specs for this 302?

Thanks so much for a great forum

Jcris

[Gary Lewis]

Yipes! You are into a complex and expensive area. For info, I have several pages on the fuel system parts, but I have them laid out poorly, so here's what I think you need:

• Fuel Systems/Fuel System Illustrations/1985 & on F-Series

• Fuel Systems/Fuel System Part Numbers/Fuel Tank Selector Valves

In the first link you'll see an illustration, towards the bottom, for 1985/87 F150/350 - 6 CYL. 300 (4.9L), 8 CYL. 302 (5.0L) & 351W (5.8L) UNDER 8500 GVW

- WITHOUT E.F.I. I think that's the right illustration - assuming you have dual tanks. And, if so, the part I think you worked on is 9189. Right?

If so, that's the fuel tank selector valve, as shown in the 2nd link. And, I'll bet the check valves were to ensure fuel is only returned to the tank from which you are running. So, w/o the check valves you may find that fuel returns to both tanks, and you could easily overflow one.

[85lebaront2]

Yipes! You are into a complex and expensive area. For info, I have several pages on the fuel system parts, but I have them laid out poorly, so here's what I think you need:

• Fuel Systems/Fuel System Illustrations/1985 & on F-Series

• Fuel Systems/Fuel System Part Numbers/Fuel Tank Selector Valves

In the first link you'll see an illustration, towards the bottom, for 1985/87 F150/350 - 6 CYL. 300 (4.9L), 8 CYL. 302 (5.0L) & 351W (5.8L) UNDER 8500 GVW

- WITHOUT E.F.I. I think that's the right illustration - assuming you have dual tanks. And, if so, the part I think you worked on is 9189. Right?

If so, that's the fuel tank selector valve, as shown in the 2nd link. And, I'll bet the check valves were to ensure fuel is only returned to the tank from which you are running. So, w/o the check valves you may find that fuel returns to both tanks, and you could easily overflow one.

Gary, Jchris, I would suspect the truck was originally a 5.0L (302) EFI model as those are the only trucks with that style tank selector unit. Also only the 1985.5 and 1986 assemblies had an internal filter. A 5.8L (351) should have had a straight forward mechanical fuel pump and the 3 port selector valve.

It seems like someone swapped in a 351 and used the old low pressure in-tank pumps from an EFI 302 to feed it (sound familiar Gary).