88 f150 acts like running out of gas

[fiveday]

I have an 88 F-150. about a week ago when I started it I could not get no power...it was very sluggish...could only go about 60 with the pedal to the floor. then after I resterted it it ran fine for awhile. It then started chugging like we were running out of gas, I slowed down and then it ran fine. now I can barely make it a block with out it starting to chug and stalling out, and then I have a hard time starting it again. I changed the fuel pump on the rail to no avail. I also changed the map sensor....still running the same. my plug wires are all new. any help would be greatly appreciated.

[FORDTRACMAN]

I'm guessing you have a 5.0 but have no idea.
Have you checked fuel pressure?Replaced fuel filter?Do you have dual tanks?Fuel pressure regulator?

[fiveday]

Yes my husband knows its a 5.0. Im typing for him while hes outside working on it, so pardon me if I leave things out. Yes he has dual tanks but only the front one is hooked up for use, he has also changed the fuel filter, and the throttle cable. The truck idles fine, when in park but after driving it a few minutes it acts up. Could it be the fuel pump in the tank?. or could it be that #7 and #8 were touching.

[steve in alaska]

have you checked to see how mush pressure you have coming out of the exhaust? Sounds like your catalytic converter could be plugged..had this happen to me one time in a Buick..choked the car to death! Took it off, and it was fine!
Steve

[mustangmike351c]

I would go with steves idea sometime the cat will glow cherry red after you drive it if its clogged up. if 7 & 8 are too close you would get a ping or a knock but it wouldnt act like the way your truck is

[fiveday]

Thanks for the help so far...... were going to check the cat converter tonight. much appreciated. right now hes changing the tank....the truck had sat a couple years.