2.8 engine won't stay running without fluttering the gas pedal the truck was't used all summer i changed the fuel filter & replaced the distributor cap & rotor i drained all the old fuel & added new & used sea foam fuel is coming out of throttle body but won't stay running HELP

sounds like a fuel delivery problem, have you had the OBD read ?the backfire could be a symptom of timing out or misfire so need to check a few things

Clean trottle body,Tune up,fuel filter,coils.

replace your fuel & air filters, add some fuel injector cleaner to gas tank, todays fuel w/ ethanol is hurting your engine, change your oil also.

Could be a dirty throttle body or a problem with the idle air control valve.
Is the check engine light on ?

Really sounds like a vacuum leak. Lean code could still be accurate. Screaming idle usually means air is getting into engine. Ruptured EGR diaphragm would vent air. Brake booster could vent air. A lot of air will show lean mix.

You may have to use different methods to test vacuum. Some use vacuum gauge to test egr and lines which dead end into solenoids. Other tests use water spray or propane gas to draw in and change rpm. You are at a disadvantage if engine does not run.

Crankshaft sensor helps set fuel volume for given rpm. Might not be counting all the rpm's, but would not account for fast idle.

Have your fuel pressure checked sounds like it might be a clogged fuel filter or a weak fuel pump.If its not within the specs then replace the pump.If the fuel pressure is low i would replace the fuel filter first then the pump if needed.

not getting air or exhaust ....its being 'choked'

Change the fuel filter.
You may have to also change the fuel pump (sounds like it is getting weak) , but the filter is the cheaper/first step in the process.

You possibly have a clogged fuel filter, a vaccum leak would cause your engine to idle high, and the oxygen sensor would set off the check engine light, but it may be worth replacing the oxy sensor given that the car is 16 years old. Try replacing the fuel filter first and see if that helps.

drain the tank change the fuel filter motor will be fine
it'll run funky until the e85 is flushed out