So, I read everyone's messages, and first replaced the fuel filter, which was easy , once I got the hang of working on the truck using a stepladder!

Once I disconnected the sensor on the bottom and actually removed the filter, I noticed immediately that one of the two wires going into that sensor was broken, but barely hanging on to the sensor itself.

My new theory (although I have not tried this on the highway yet) is that the wire contacts and then disconnects, causing the sudden loss of power, then the gain of power.

The filter had lots of floating crap in it, by the way.

Thoughts?

 

The sensor is for the "water in fuel" (WIF) light, it will not affect the truck if it is disconnected or removed entirely. Lots of floating crap in the filter could well be the cause of your power loss. Clogged filters are an odd thing, you'd think there would be a gradual loss of power as the filter gets restricted, but it seems like sometimes a truck will run great up one hill, then fall on its face on the next. Change the filter and the problem is fixed. Odd.

 

Floating crap in the filter is not good -- make sure you keep an eye on it.

Dave is right about the WIF wires.

 

Well, you guys are right about that WIF sensor and wires. No effect. Today, however, the truck lost power at any speed, not just highway speeds. What's weird is that yesterday it didn't do it at all, but this morning I had to turn around and take it back home and get the car.

I think it's the fuel pump REALLY going south now.

 

Just a thought,maybe whatever is floating in the filter plugged the fuel line.?The only problem with this theroy is there is a screen on the pick up in the tank. I'm not sure how to fix or check this?! Maybe pull the filter and pull the fuel cap and introduce compressed air into the tank? Or it could be the lift pump.? Someone out here has the right answer!!Good luck

 

Just a thought, I had a 72 Riviera that would lose power and stall sometimes, mostly going up some hills. The mechanics did everything, rebuilt carb, cleaned fuel lines, filter you name it they even did some special type of steam chemical bath on the parts. Finally they took out the gas tank cut it in half and it was filled with rust and crap. They cleaned it out welded it together and that fixed the problem. .

 

I would guess you've got junk in the system now. Was the truck sitting for anytime at the place you bought it from? If crap is getting to the filter, that means it's going thru the lift pump, so yes, it could be hurt at this point. I'd pull the filter off and see if this one is full of crap already

 

Hi Furious,
The previous owner did tell me that he let the truck sit for 6 months before selling it.
If there was stuff in the tank, I'm kind of surprised that it would stir up now, after I've put 2000 miles on it.
Sunday I replaced the filter.
I think the next thing is the fuel pump.

 

Denis -- There is crud in the tank as evinced by crud floating in the filter when you changed it. I would highly recommend draining the tank, taking it off the truck, and cleaning it and the pickup tube. The tank is plastic, so whatever is in it can be washed out. It is possible that something got stirred up recently, or that you got a bad load of fuel, or that the pick-up tube just started to disintegrate, OR you might have some bad lines from the tank, but look in the filter and see what you find, and then clean everything from there back.

Good luck,

Alec

 

Hi Alec,

I was hoping NOT to have to remove the tank, considering diesel is stinky and the tank is holding somewhere around 20 gallons. What do I do with all that fuel?

What do I clean the tank with and where do I put the gunk?

To be safe, I'm picking up a new fuel pump tomorrow, so it might be as good a reason as any to remove the tank.

Thanks!

 

I had bad lines leaking last summer. I disconnected them and replaced with rubber lines from tank to lift pump. The crud is most likely coming from the tank, from years of bad fill-ups. You could at least try changing the lines first to eliminate that possibility. Fortunately, I have a flat bed with all kinds of room under there. When you end up dropping the tank, it'll be a good opportunity to clean the mounting straps, in case there is anything wearing against the plastic. We just had to replace both tanks on a 95 FORD with low mileage.

 

I meant pull the new filter off to see if it's already full of junk. This would indicate a lot of crap downstream, probably the tank in that case

 

Hi Furious,
That's a good point about the new filter. I somehow missed that in your post. Today I'm working on the truck and I'll check the new filter, then put on the new lift pump.
Somewhere on here I saw a post detailing the procedure for putting on the new pump and priming the pump by lifting the lever 30 times or so.
Can someone send me that info?
Thanks!

 

When I changed my lift pump I just opened the bleed screw on the filter mount, then pumped the lever until I got fuel, maybe 5 or 6 pumps. Tightened the bleeder down and she started right up.

 

Are we talking 1st gen. or 2nd gen here , if you have a second gen , and have crap floating in the filter , I would be remove the lift pump and take the top cover off and cleaning the screen in the lift pump, cuz if it is coming from the tank it is also in the screen of the lift pump , I pulled a fitting from the inlet of the fuel filter the other day and it was almost plugged with woodchips , so I pulled the lift pump also and it was also plugged with woodchips , so the tank had to be removed and lines cleaned out.