You guys are great and have helped me already, thanks!

I have a 95 f150 4.9 that was abused by its previous owners.
It's been having entermitint issues, recently died out after driving up a long steep grade on a hot day. It started running rough and then died out. It's done this a few times, my mind went strait to fuel pump.
Now it's bogging down under load, going up hills with accelerator fully pressed it bogs down. If I let off and only give it half throttle it does better and even seems normal.
So, here's what I've done recently because the issue:
I took apart the throttle body and cleaned it, cleaned out the IAC and installed new gaskets and a new TPS.
New spark plugs, rotor, cap and wires.
Replaced the grounds to battery and starter.
New fuel filter.
Replaced some cracked and worn out vacuum lines.

I hooked up a fuel pressure tester and with the engine off and the fuel pump on continuous it was reading at 40 psi. 10 psi below what it should read. Engine running it reads 45 psi the minimum it should be while running.
I changed the fuel filter and it went up to 45 with the engine off pump on, still 5 pounds lower then it should be.
I tested the fpr and it does seem to work, pressure raises when vacuum is unplugged and returns when plugged back on.

So I've come to the conclusion it's the fuel pump which I will replace as soon as possible, the front tanks fuel pump is already dead so I'm doing both same time.
Am I on the right track here? What do you guys think? If anyone has any input or ideas please don't hesitate.

 

replacing a known bad fuel pump is never a bad idea.

 

Thanks Joey2fords! Lol
I forgot to mention it's been starting real hard after sitting, coughing and sputtering to life.

 

It sounds a lot like what happens when a fuel pump is starting to fail.

 

Update:
So I replaced both fuel pumps, the mid tank never worked and as it turns out was full of rust and crap and the float was missing. The aft axle tank pump was 10 pounds bellow the psi it was supposed to be.
So it was all back together, the fuel pressures was reading good on both tanks, I started driving home up the mountain (I live in Kona, 50 to 3000 ft. elevation in 10 miles) and the truck starts sputtering and losing power so I switch to the front tank and it runs great and up the hill I go. Make it home fine. I said screw it I'll deal with it tomorrow, so today I tested the fuel pressure and the rear tank was at 30 engine off and pump running constant. The front tank is great, truck runs perfect, it's at 50 psi engine off with the tester bridged.
I checked the connections and bothe front and rear tanks are hot and receiving 12 volts.
Could it be the new pump I put in the aft axle tank is bad?
I've seen it before, in an explorer installed a new pump went bad in two weeks, replaced it and went bad again, went to a deferent manufacture and it worked fine after that.
What do you guys think? It runs great on the front tank.

 

It is possible that the pump went bad, unfortunately. As you discovered with the Explorer, sometimes parts go bad really fast. Some are even junk right out of the box! I can't imagine the colossal pain in the rear it would be to have to remove the old pump again. I imagine the "front" (mid) tank would be easier to drop than the rear tank, if you were going to do it from below. I'm guessing you probably took the bed off to replace the two pumps the first time, since that is the easier way. Buy the best quality pump you can afford. Good luck!

 

Thanks phoskins, I did take the bed off and replaced bothe pumps the same time. So I will be doing it again, at least it's only 6 bolts.
The pump was a Delphi, I was under the impression they were good quality. I'll look for the best one I can get, the motorcraft one was $500 here at the dealer.

 

I called and spoke to the parts store I bought the pumps from and they are going to give me a new pump of a different brand. They said they have had a lot of problems with that specific pump and make, Delphi.
Ever since they started making the pumps in China instead of Mexico. Figures....

 

Great.... I just put a Delphi in my rear tank....

 

that's what i get the privilage of doing on my friends 95 f-150. i finally got the filter off(what a pain).don't buy the cheap tool to remove the quick disconnect,the butterfly types don't work so i cut the filter off so i could work on it easier and when i dumped it the filter sludge and dirt came out,not good. i think i will take the bed off it is much easier..

 

Second update: After talking with the manager at the local car-quest I pulled my bed again and removes the new faulty pump and exchanged it for a new pump of a different make. I put that pump in and checked the fuel pressure and it was good, 48 psi while engine running and 55 psi engine off pump running. Put the bed back on and then checked it again still good! I drove it around doing some errands and its working great.
I can say I'm pretty quick at removing the the bed and changing out pumps now ha!

So if you're experiencing hard starts, intermittent rough running, and your engine sputtering and dying out with high ambient temperatures and after the engine is under a heavy load check your fuel pressure.
Like I've experienced in the past a new pump doesn't always work, or work for long. In my case the more expensive pump was still made in China.

 

So now the new mid tank fuel pump has failed! I'm going to bite the proverbial bullet and get two motorcraft pumps. Screw the after market pumps they seem to all fail sooner or later.