Engine/Transmission (1998.5 - 2002) Lift Pump Problem?

[StevenJ]

I have a 2001. 5 4x4 automatic and seem to be having an unusual problem. When using WOT from a slow speed such as getting onto the freeway, the truck initially accelerates well then quickly feels as if you have backed off of the throttle. It continues to accelerate but less than it seems it should and feels like it is holding the gear longer than it should. The truck only has 14000 miles. Does this sound like it could be the dreaded lift pump? The truck starts OK and does not stall.

 

[Truckie]

Yes that is what it seem to be. I have a 2001 with the 5 speed and it acted the same way that you are explaining. I think what happen is when you hit the go peddle and start of WOT the fuel cannister is sucked dry by the the VP and the lift pump cant keep up with the demand of WOT. I would get it checked ASAP and check to see if you have any codes set in the computer. Hope this helps out some.

MIKE

 

[cwarner]

I would lean more towards the TV cable adjustment. On occasion my truck will actually hang in gear until I lift just slightly. I haven't had a chance to adjust mine since it's been too cold out and now it's snowing. I will live with it until spring.

I will repost with the procedure on how to adjust it.



This is courtesy of LSfarm (thanks Greg),

first remove the black plastic cover that is just infront of the air 'horn' on the intake manifold, This cover has two push plugs that look like phillips screws with washers. they will back out with gentle turns of a scrwedriver, but if you push in to hard, they will not back out. once the 'screw' is backked out about 1/4" then use a small flat blade to pry under the 'washer' and the whole pin will come out. with the two pins out, you can remove the black plastic cover you will see a thin cable, about 1/16" diameter coming out of a black plastic 1" square box of fitting on the bottom rear of the throttle 'box' you just took the cover off of .

On the cable will be a small black plastic 'bullet' looks about like a . 22 cal bullet but made of plastic. The front pointed end of the bullet is probably way to the rear of the front of the black square box the cable comes through. . if the cable is adjusted so that the bullett is closer to flush to the front of the 1" black 'box' or mount, then the upshift will come sooner, [lower rpm] but the downshift [passing] will require more pedal to get a downshift.



the adjustment is done by looking to the outside of the black mounting block, where the cable exits the box, there you will see a fragile white plastic clip. This clip is part of the cable assembly, and cannot be purchased separate, so be carefull!!



the white clip is 'U' shaped with the open ends facing the engine. [the 'U' is on it's side] You have to open the U up, sort of make it a 'V' with your finger nails or VERY carefully with a small flat blade screwdriver. the problem is that the darned thing wants to spring back to a U all the time, so you have to push back each side a little towards the fender [towards you] and then gently pry up the other side and push it back without the other leg jumping forward back into it's locked positiion. Sometimes a few cuss words helps.



the Plastic U moves only about an 1/8th inch or so towards the left fender, then the cable housing is able to slide fore and aft in the black plastic mount. move the cable forward only a very small amount, like 1/16" or so, about the width of the cable. Then snap the white plastic clip back in place. It fits in slots in the cable housing, so be gentle, and you will feel it fit in place, and both legs of the U will snap in place.



the test drive: if you went too far, then the truck won't downshift to a lower gear easy enough, if not far enough, then it may still hang up on the 1-2 shift. personally I like an aggresive downshift, and can live with having to lift the pedal slightly to get the upshift, though this is personal preference