Truck won't start. Fuel pump?
 

Hey all, a few weeks ago I was driving on the highway, and my truck stopped being able to accelerate. I would push my foot down and nothing, no revs, no power. Then it died. No start. I got it towed home, removed the bed, was looking at doing the fuel pump. But I figured I would start small and do the fuel filter first. I did that, and then it started right up. This was on Friday, and I did not drive it until today. Today, thinking I was all set, I put the bed back together, and went to take the truck to work. Same symptoms, next thing I know I have another dead truck on the side of the road. If the true issue is the fuel pump, why would it have been able to start up and drive between now and putting in the fuel filter? Doesn't no gas mean no gas? I'm going to go back in and replace the fuel pump, but I'm really not sure what to think about how that could or should work. Does anyone have any insight on why that may be, or what the issue may be if anything other than or in addition to the fuel pump?
Any help is always appreciated.

The truck is a 1999 Mazda B4000 v6 4x4.

To rule out an ignition issue, spray a bit of starting fluid into the intake tube or throttle body when it refuses to start.
Could be electrical, may be faulty inertia switch.

Also check your fuses for bad connections that are to do with the fuel circuits.
There's probably a relay in there too.

I have a 3 litre Mazda, so I can't say for sure where it is on your 4 liter, but it's a place to start.