350 Cummins No Power On Acceleratio

[BULLDOG2058]

I recently started restoring a 1980 F700 Cabover Mack. 350 cummins, 10 Speed. The tractor had been setting for about 5 years. I installed new batteries and she fired right off. I drove her about 30 miles home with no major problems. I've been starting the tractor at least weekly while working on it and no problems. Last nite I took her out to knock the cob webs off her and she started fine but had no power on acceleration. I just barely got it into fifth gear before she ran out of steam. I changed the fuel filter today with no improvement. Stumped and aggrivated.

[Underdog]

I recently started restoring a 1980 F700 Cabover Mack. 350 cummins, 10 Speed. The tractor had been setting for about 5 years. I installed new batteries and she fired right off. I drove her about 30 miles home with no major problems. I've been starting the tractor at least weekly while working on it and no problems. Last nite I took her out to knock the cob webs off her and she started fine but had no power on acceleration. I just barely got it into fifth gear before she ran out of steam. I changed the fuel filter today with no improvement. Stumped and aggrivated.

truck has been sitting 5 years so has the fuel. Drain the tanks, make sure all the fuel lines are open & in good condition to ensure proper volume of fuel, and start again with fresh fuel and filters.

Also check that no brakes are dragging.

[Bollweevil]

I recently started restoring a 1980 F700 Cabover Mack. 350 cummins, 10 Speed. The tractor had been setting for about 5 years. I installed new batteries and she fired right off. I drove her about 30 miles home with no major problems. I've been starting the tractor at least weekly while working on it and no problems. Last nite I took her out to knock the cob webs off her and she started fine but had no power on acceleration. I just barely got it into fifth gear before she ran out of steam. I changed the fuel filter today with no improvement. Stumped and aggrivated.

Check the aneroid diaphragm. Midway on the back side of the pump a steel line goes up and makes it's way to the after cooler. Disconnect the line at the after cooler, and apply no more than 15 lbs. air pressure. A hand held vacume-pressure guage is best. It has to hold pressure. Before you get too involved, old fuel lines are prone to come apart inside and suck together. Make up, or use a known good feed line , run it into a five gallon container, and go for a short ride. short because return fuel will still be going into the tank.

[Olivetroad]

I recently started restoring a 1980 F700 Cabover Mack. 350 cummins, 10 Speed. The tractor had been setting for about 5 years. I installed new batteries and she fired right off. I drove her about 30 miles home with no major problems. I've been starting the tractor at least weekly while working on it and no problems. Last nite I took her out to knock the cob webs off her and she started fine but had no power on acceleration. I just barely got it into fifth gear before she ran out of steam. I changed the fuel filter today with no improvement. Stumped and aggrivated.

I had a 1980 White Road Boss with a 350 big cam Cummins (855 block) years ago and I lost all power one evening pulling a lowboy. I replaced the fuel filters and no improvement. An old hand got on the radio and said to take the plug out of the top of the injection pump and remove/replace the small filter under the plug. It ran like a champ after I did that. If I remember correctly, it was just a stud looking thing on the top of the injection pump that unscrewed and there was a little screen filter under it. He was suprised mine still had the filter, he said most drivers threw them away soon after the truck left the dealer lot. I went ahead and replaced it, but the engine had two filters before the pump that should be catching everything. Yours may be different, hope this helps-