The last two afternoons driving home my truck has backfired. My question is what causes backfire? Is this something I should worry about?

 

google backfire

 

Check timing.

 

Cat causing a back pressure condition, injector hanging open, bad fuel pressure regulator, timing....... I would worry about it.

 

Don't have cats, PO cut it off.

I ordered a fuel pressure tester and it should be here anyday. I will check fuel pressure and timing this weekend.

The truck has what I think is a fuel problem. It skips/surges under any touch of the gas.


Thanks for replys guys!

 

Hate to start w/ the completely mundane, but fuel filter?

 

i think i've recommended fuel filter changes to like 20 people on the forums. its cheap easy and quick and actually helps with more problems than people seem to think until they actually change it

 

I not saying its not the fuel filter, but I did change it about 3 weeks ago when I started down the EGR valve road.

I really think its going to be a fuel regulator or maybe a injector problem. I won't know anything else until I can test the fuel pressure.

Thanks for the replys guys! will let post the results of my fuel pressure test after I get it done.

 

If the smog pump valve is malfunctioning it can cause backfiring too. So will exhaust leaks.

 

It's a 302 by the way. You may see excessive fuel pressure, or pressure quickly dropping after the engines shut off.

First would be the regulator (sometimes you'll see fuel when you remove the vac hose).
http://www.fordfuelinjection.com/?p=41

Second would be injectors failing to seat closed.
There used to be a great injector cleaned that was in an aerosol can. It screwed right onto the needle valve on the injector rail. I think NAPA carried it. You could always run a can of Seafoam in the gas. Or Lucas injector cleaner.