Ok guys, long story, I have a 2008 F-250 6.4. Last year my son wrecked the truck. It wasn't to bad just a grill and bumper, but the truck sat for approx. a year or so and not started due to the fact i didn't have the money to fix it. Well when i got the funds to fix the truck I went out to start the truck and the Batteries were dead, so I jumped the truck off and off to the body shop. while en-route i noticed the fuel gauge registered E and the dash info stated o-miles to E (still does w/plenty of fuel). The truck's power was up and down the RPM's were up and down, in drive while under a load. (in park idles fine) and the truck runs great some times and not so good other times. kinda like surging. The tow/haul does not work now either. All this happened all at once.

Here's what I have done thus far, I changed all the fuel filters drained the water separator, and checked the fuses. My question is, If the sending unit is bad can it affect the engine performance like this and where should i go from here?

Any thoughts? ohh and no codes present

 

Well, you're really going to have to check the wiring. I would start with the lights. Yes, the lights. The tow/haul button and the fuel sending unit I wouldn't think would be related, but I might be wrong with that. Does everything else work? Brake lights, marker lights, headlights, fog lights (if it has them), turn signals, hazard lights, radio, air conditioner and heater. The third brake light in the top of the cab too. Does the alternator charge the batteries? I'm thinking you may have a ground issue.

 

all lights work new
batteries and the alt is charging fine