Long story but I'll try and make it quick.

I bought this 95 F150 for my grandparents 5 years ago. Their old chevy finally quit on them and they needed a new truck. They drove it around for a while and the only problem they had was it needed a fuel filter. My grandpa can no longer drive so I took the truck back. When I got the truck back it had been sitting for about 6-8 months with no one driving it.

When I got the truck back I changed all the fluids and it ran fine. I planned on keeping it as a spare truck but then a drunk driver hit me and totalled out my truck. So now this is my primary driver.

I was driving it a month or so ago and it just stalled on me. I towed it to my garage and dropped the fuel filter (which was dirty) and filled it up with gas and it ran just fine. Then, a few weeks later it died on me again. This time I decided to drop the tanks, wash them out and replace the fuel filter again. I also replaced the fuel pump relay for S&G's. To my suprise the tanks were not dirty. I blew out the fuel lines and put everything back together. When I did this I replaced the spark plugs (which were horrible) and the wires. The truck ran really good then. I drove it for about a week then yesterday when going back to work, when I gave it gas it hesitated and acting like it had no power whatsoever.

A few blocks down the road it stopped and would not run. I limped it to the side of the road and switched tanks. When I did this it started right up and ran fine. Now, this morning when I came to work it started hesitating again and acted like it had no power. When I give it gas it stalls a bit then takes off. Its not as bad as it was yesterday but I'm running out of ideas since I've never worked on this type of Ford before. I first thought maybe it was just the fuel pump in the front tank going out, but if it still keeps on doing this on the rear tank then it has to be something else.

Any help would be greatly appreciated.

Oh, and on a side note, when I am running the AC (which blows ice cold), if I ever stop at a light for more than 20 seconds the cab starts to smell very strongly of exhaust. I have no idea where to start on this problem.

EDIT: Well that didn't take long. I left for lunch from work and the truck was running great. As I am pulling out of the driveway to go back to work the truck dies on me again. Try to start it and it sputters and barely stays running. I start driving down the road and same thing, when I give it gas it acts like it has no power and tries to die on me. I turned around and jumped on my motorcycle and brought that back to work. I guess its not the front fuel pump. Any suggestions?

 

have you checked for codes tried pulling them. how about a fuel pressure check. what kind of engine did not see it in your post. until then do a visual inspection hows your battery voltage battery connections any noticeable rust or corrosion issues in the engine bay. any access fuel in either fuel tank. what type of fuel filter plugs and wires. does your fuel gauge read and fresh fuel in the tank. start with fuel pressure and is your MIL on. when you pulled the relays did you do any probing at the contacts anything that would have spread the contact pins. try to do your testing when the engine is having its fit if you can. sorry for all the questions but just want to make sure.

 

Check fuel pressures at the fuel rail, it sounds like a bad FPR.