Is it the Lift pump?

[stick]

My neighbor's 2001 HO seems to stumble every once in awhile (like the fuel was shut off). He took it to the dealer yesterday, and ofcourse they found nothing wrong !

I don't keep up much with the 24v's, but have been seeing the posts on the lift pumps going t*t's up, and was wondering if this might be what he is seeing?

If it is, where do we go from here?



Thanks - Stick

 

[LSMITH]

Stick, there are two ways to tell the lift pump is shot. The recommended way is to check the pressures with a gauge. I have been using a temporary gauge for a couple of years a couple of times between oil changes. The guys with full time fuel pressure gauges have the best setup. The "other" way is to change the fuel filter, and hope the filter will fill when you put it back together. If it fills, great. If not then the cussing starts. Believe it or not this is how a bunch of dead lift pumps have been found.



The dead lift pump nearly every time has no symptoms until you pull the filter or check pressures. Power can be down slightly but I really doubt you could tell. If the stumble is in the upper RPM or at heavy throttle conditions only then it very well could be a clogged filter or lift pump dead and blocking fuel flow. If the stumble is in the lower RPM and varying throttle conditions it will more than likely not be a fuel supply problem.



For a stumble that happens all over the map guys have reported new injection pumps, MAP sensors, APPS, and ECM reflashes have fixed the problems.



Get some more information and we will surely try to help your buddy.