I have a 01 7.3 4x4 w 215k miles. Started losing power and surging at highway speeds. Replaced the fuel pump and crank shaft sensor. Now will some start and idle, but will not run once in gear. Has anyone ever experienced, if so what is the solution

 

How did you determine that it is a fuel system problem?

Is this a gas engine or a Diesel? (Sorry, I don't know trucks that well)

In gas engines stumbling and surging is often caused by vacuum leaks and/or ignition problems, or a dirty MAF sensor.
If it is a fuel system problem it could also be a clogged filter, dirty injectors, bad fuel pressure regulator.

If it is a Diesel it is out side my range of knowledge.

 

Have you done anything with the fuel filter(s) ?

 

From what you describe about surging /power loss, or a flat throttle under higher throttle angles, sounds like the micro screens in the fuel tank module are restricting the volume/pressure.


Cheap test,, find a 'steep' long grade where you'll need to go deep into the throttle for as long as possible. The demand for fuel will be high which translates to fuel volume. If the screens are restricted, the engine will bog down and/or the throttle will go flat. Once it's starts to stall or hesitate, back off the throttle 'slightly' going up the grade and if the engine power improves and smoothes after a short time, the screens are plugging..

They get overlooked a lot, and at your mileage could quite possibly be the cause. The screens are inside the plastic tank module which requires the tank to be dropped. There's also the larger screen or strainer, but the micro screens are 'inside' the white plastic housing and the reason they get overlooked. There are tabs that need to be 'carefully' released on the housing to access the screens for cleaning..

 

Thanks for the advice. The fuel filter was replaced. Haven't checked screens yet. Will try and do this weekend.

I keep getting the theft warning light when I start the truck. Will that cause it to shut down?
If so, how do you reset?

 

The truck will crank/start with the theft light on?

Steady theft lamp On?, or flashing? Is it everytime you try and start the truck?, or just ocassionally?

Try and cycle the key ON until the theft light stops flashing (if it is flashing) turn the key back OFF and remove the key and wait 10 seconds, cycle the key On and then restart, does the light go out?

If the theft light was On, and the truck started it souldn't cause a drivabilty/power problems. There's a few other possible causes for power loss, turbo ect. but given the history of the screens causing poor fuel supply,, something I would check. Try the 'grade test' if you can, and if it proves out to be 'very predictactable' as far as throttle angle and the failure occuring, then you might try checking for adequite supply before pulling the tank..

You could (with a helper) empty the fuel filter housing with the drain lever, then, with the cap off have someone turn the key ON for just a FEW SECONDS or so as you watch the incoming fuel. It should fill the housing 'very quickly'. Be 'carefull' to not allow the fuel to spill out of the housing..

You can also remove the 1/8 pipe plug in the ends of the head (fuel rail) and put a guage/volume tap and test for spec pressure and volume that way. If the screens are restricted, usually the fuel in the rail (or may show in the filter housing) will not only be poor volume, but may contain air/bubbles with the incoming fuel..

 

Thanks everyone for the advice.

Pulled the fuel filter, bowl filled quickly. So getting fuel to the motor was not a issue. Praying it was not the injectors. Then I rememberer the theft light and watched it more closely.

The theft light was blinking rapidly at first, then a pattern developed. Single flash, pause then six flashes. Pattern repeated a couple times then went back to a constant flash. I forum searched this prob and have found the solution. I hope!!

The flashing theft light meant low voltage, pulled the batteries, had them tested and one came back with a dead cell. Put the new batteries in and she purred like a kitten. I guess after we replaced the fuel pump we damaged the battery trying to crank it.

I seem to be replacing the batteries every 2-2.5 years, is this normal. I was told to rotate the batteries, side to side every six months to make them last longer, has anyone else ever been told this.

Again, THANKS everyone for your help. We got this truck back up and running in time to put our 08 6.4 liter in the shop. The dealer says the injection pump need to be replaced, cab off repair. Thank god for the extended warranty.