saturnxjc

Fuel filter and pump are good. I let it set for a day and started it up and drove for 50 miles everything was working great. I stopped and put $40 of gas in it. I drove two blocks and the same thing started again and it will only drive 35 to 40 mph. I am wondering if this has a sending unit in the tank and could this be the problem?

I recently bought a 1987 Mallard motorhome with a 454 engine. The fluids are good and check out good. I put new spark plugs and spark plug wires on, new rotor and cap, new intake, air and fuel filter. My question is, when I first started I drove for about 5 hours and at 65 miles per hour and and all of a sudden it slows to 40 miles per hour. When this happened I filled it up with gas and it was fine for a few more hours then I parked it overnight. The next day I ran all day with no problem. I thought it was fixed, but again I drove a half a day and it began to slow again and I filled it up but that did not work. The only thing I did not do was put in a new fuel pump but when I turn the key I can hear it turn on.