Would like opinions on an intermittent issue I am having with my 01 HO 6spd truck….
Sometimes it pulls strong, sometimes it is a little sluggish ( almost like the quadzilla has been turned down a level). Then occasionally for a moment, it will loose power and then catch back up. Usually when this happens it is so brief you wonder if it was imagined. My gut says the vp44 is on its way out. Wondering if a TPS could cause this? Or any other ideas? This is the same truck that appears in my profile.

 

I'd guess APPS (basically the same as a TPS, but apps is a better search criteria).

Mine started doing that and then randomly went FUUUUULLLL throttle a couple times and I decided it was time! I got the Timbom (sp?) APPS for a fraction of the OEM cost and it was easy. Kinda sensitive at the low end of the throttle spectrum, but not too bad. Otherwise smooth.

 

well for starters.
have you pulled/checked for codes. if concerns of APPS do a APPS reset/recalibration that is free.
if you have codes post them and then we can troubleshoot.

if no codes than take all battery cables and grounds both body and engine and clean them.

when my apps was acting up it wasn't a loss or sensation of power. it was a flat spot in the throttle band. example 57MPH and after pushing the throttle a bit it would not respond untill I increased enought pedal and fuel past that spot in the throttle.

also unhook your Quad and see if the issue is still there. eliminate all of your options.

any weird smoke coming out when the engine is doing this. is it constantly doing the same issue around the same speed and rpm?

 

I experienced similar a few years ago - flat spot in the throttle band. It was due to a failure in the injection pump. I understand this happens a lot due to a weakness with the lift pump set up on the earlier ( mine is 2002 ) trucks. ONe recommendation which I now follow religiously is to replace the lift pump every 50 to 60 K miles. It wouldn't hurt to have a fuel pressure gauge to tell you when the lift pump is getting old - something I need to do also.

Jim

 

Check fuel pressure and replace lift pump right away. lift pump $200.. Injection Pump $1000 ..Labor for injection pump $3000 at dealer in CA.



I see you have a K&N filter, if you have to much oil on those filters it can get on the MAP sensor (called Boost sensors on diesels) it can cause erratic power and or send the engine into limp mode.
My truck started performing like that until stranded. I would pull over place it in neutral and it would rev fine, put a load on the truck and no power because no turbo.

Mike