i got a 92 b250 van with a 3.9 L i was driving then it started to act like it wasn't getting gas and it was back firing so i put a new filter and fuel relay on it then it will go about 5-6 miles down the road and do it all over again let it sit for a while it will fire go down the road do it all over i am lost please help i am stuck out of town

 

How is your fuel pressure/flow? If the pump is weak it could fail to supply enough fuel to run the engine properly.

 

When was the last time you replaced your catalytic converter? The backfiring and running ok for a bit then not sounds like that is where the problem is. Crawl under your truck and bang on the converter a few times (after it has cooled down). If you hear a rattle inside then it definitely needs replacing. What happens is little pieces of ceramic start moving around when you accelerate and then block the exhaust tube. When you let off the gas it may start running normal again.

 

Fill up your gas tank. It will cool the in tank fuel pump and allow it to work, for a little while longer anyway. If it behaves exactly the same with a full tank, then you might be able to exclude it as the culprit.

When it stalls, with your ear to the filler tube, can you hear it when the key is first turned on for about 2.5 seconds?

If not, try slapping the bottom of the tank hard right after turning the key on and listen.

Mine got real noisy right before it failed.

You can also determine if it is a fuel issue by spraying throttle body or carb cleaner down the intake when it stalls and will not start. If it starts on the spray cleaner, then your pump is not getting the fuel to the throttle body or past the injectors. Doing this excessively can foul the o2 sensor.

Also do the key dance and search for codes

 

If you go this test route then maybe you're not going to want to fill it. Just above a 1/2 tank would be best only because IF it is the pump then the tank has to come down to replace it. No one wants to lower a full tank of gas, or wants to deal with draining one either.

To me, it's a lot easier to just connect a fuel pressure gauge and take a reading both when it's cold and after it stalls. If there's a significant difference after it stalls, then you know the pump is shot.

 

Alloro,
Perhaps I want everyone to experience the joy of removing 25 gallons of gas from a tank before dropping it. But then you'd have to do it in the dirt on the side of the road in Baja to equal my joy. Serves me right for noticing a loud pump, then driving under the sword of damoclese.

A fuel pressure gauge would be great for diagnosis, if one is available.

 

Next you'll be telling me that you want to steal candy from children and kick a few dogs.

 

Those were at the top of my to do list today, and already crossed off.

Just kidding, I love dogs.

 

With or without a marinade?