Does anyone know how many fuel filters are on the 1988 F150 and where they are at? I don't have the owners manual, can't seem to find it on Google, and Hayne's doesn't note the location. It's a 302 with dual tanks. I've heard there are 2, one for each tank, and also have heard there are 3. I would certainly be thankful if someone could clarify how many and where I can find them, thanks!

 

One fuel filter on the inside of the driver side frame rail near the engine firewall.
One sock on each fuel pump located inside each gas tank.
There is no filter inside the tank selector valve which is also mounted on the
inside of the driver side frame rail near the transmission cross member.

 

What HE said….

 

Thank you very much kind sir! I've been having issues with the front tank. When I switch over to the front tank, it will run for an intermittent amount of time(sometimes 30 seconds, sometimes 10 miles) and then the engine will start to sputter and I'll get no response from the gas pedal as if the engine is not receiving fuel. The rear tank works fine so I'm running that now. I was thinking if there was a fuel filter per tank I'd start there, but since that is not the case I'll have to look into the fuel pumps. What is the sock that is on the fuel pumps? Is that a changeable part that could cause this issue that I could test? Or is it better to change the fuel pump as a whole? Thanks again for clarifying the fuel filter numbers and locations.

 

Here's what the filter looks like for the in tank pumps.


Sounds like your problem is either the tank selector valve which is mechanically operated and switched by the fuel pressure is bad or the in tank pump in the front tank.

Example if you switch tanks and there is not enough fuel pressure from the front in tank pump to switch the mechanical valves inside the tank selector you could be siphoning gas from the rear tank because the valves aren't 100% open or closed.

There are 6 hoses at the tank selector valve. The two in the front are the supply and return lines. On the back there are four hoses. Two hoses for each tank. The larger diameter hoses are the supply and the smaller the return.

To verify if the front in tank pump is working, disconnect the large hose coming from that tank going in to the back of the tank selector valve. (To disconnect the hose you use a flat blade screwdriver and pry up on the plastic clip so it's half way up). You can then pull the hose off. To reinstall the hose you push the clip back down and then slide the hose back on. You should hear a click which is the locking tab. Tug on the hose and verify it's locked in place. If you break a clip they are available in the Help isle in most auto part stores.

Place the end of the hose in a bucket and crank the engine. In ten seconds you should see a minimum of 16 oz of gas.

If that looks good the problem is most likely the tank selector valve is not switching the mechanical valves inside of it. To test that problem reattach the larger supply hose back to the tank selector valve and disconnect the large supply hose at the output of the tank selector valve. Crank the engine again for 10 seconds and see if you get 16 oz or more of gas. If no the tank selector valve is bad.

If you're going to do this for more than a couple of minutes, I'd disconnect the electrical connector at the high pressure frame mounted pump because you don't want to run that pump dry.

 

Check the line between the high volume pump and lift pump in the tank. That black holding reservoir on the fuel rail contains a filter, too. On some trucks that is the only filter. Since many people don't know about that filter and it flows less and less. The high pressure pump is then under stress and makes a lot of noise and will fail early.

 

We had an 87 that had a filter in the selector valve too.

 

My money is on the pump. Once it starts heating up, it's done. Been there. Good luck.