What would u try next Fuel filter or fuelpump

There may be a fuelpump relay in one of the underhood fuseboxes. You can try some searches for 1988 F150 fusebox diagrams to find the location of the relay. The reset of the inertia sensor (safety switch) was a good try but if the fuel pump relay is bad, there will be nothing to reset because there will be no power. There can also be a crankshaft sensor which needs to generate a signal to tell the fuelpump to run.

you have a bad fuel pressure regulator it is located on the fuel rail

There are fuelpump relays for electric fuelpumps. You can have a bad fuelpump with either a mechanical or electric pump. You can have a clogged filter.

You can try Autozone.com and register your vehicle for free. Then you can get wiring diagrams and fusebox diagrams for the electric relays. Then you can find out which system you have.

It certainly sounds like you are on the right track since you discovered its a fuel problem.

sounds like the fuel pump or filter needs replaced. pull out line off filter underneath and turn key. if fuel comes out slow try replacing filter and trying again. if pressure is still low fuelpump is bad or a blown fuse or bad relay.

Hello, I looked at the Reports for TSB's (Service Bulletins) for your vehicle and there are none for this problem. There are a few things that you can try to replace that are not expensive. The fuel filter and some Relays.

I would suspect that aside from using additives to the fuel, there can be only a few possible problems. The fuelpump is either running when it should not or there is a ground problem. For the running when it should not, there are Relays for the fuelpump and I believe a PCM Relay which can turn the fuelpump Relay on.

These Relays have more than 1 set of contacts in them, and 1 set may work fine and the other set may be sticking or failing to make contact. Sometimes it is a problem like yours, an underlying long term problem that causes a part to fail over and over. What I feel may be happening is your pump is not shutting off when it should or something is grounding through your fuelpump because of a bad Relay.

The Power side of your fuelpump has a fuse, the Ground side does not. If the Relays stick and allow a different device to ground through the fuelpump, that could be your problem. I would try a new fuel filter and a few new Relays. They are in the Powerbox under the hood and should be labeled. They would be handy as backups as many are identical. Just mark them for ID.

Fuelpump secondary circuit high. First try changing fuel filter, it is probably plugged which is over working your fuelpump. If filter was or is changed & problem persists will most likely need to change fuelpump.

try it and see

you do not, theres no fuel filter to change, theres a filter screen inside the tank on fuelpump, this only gets replaced when fuelpump goes bad and needs replacing,ive never changed a in tank screen unless i was doinng a fuelpump, hope this helps.

Only one fuel pump.

go to auto zone and have them run the diagnostic test on it if the code is 171 or 174 check fuel filter $8 or mass air flow sensor $120