Hi All,

I am at a loss currently for why my 02 ranger won't smoothly accelerate under load above 4k rpm when at operating temperature, I would greatly appreciate your help. When accelerating under load and hitting 4k rpm, the truck seems to jolt and cut (see first video, its apparent). The issue does not seem to occur before it hits operating temperate, on a relatively cold run it revs up to 5k rpm just fine (there are no overheating issues I can find). When driving normally, anywhere below 4k rpm the truck drives perfect, only at the high rpm. The second video uploaded is a clean pull to 5k rpm soon after starting up, which is the behavior I am looking for at all times. The issue also occurs at freeway speed and the truck downshifts.

This is what I have replaced on the truck so far, it is at 142k miles:

-Serviced MAF
-IAC sensor
-spark plugs
- wires
- distributor
- serpentine belt
- fuel pump
- fuel filter
- K&N intake
- cleaned throttle body

I am thinking of next replacing the PCV valve which has seen better days, but would love advice on what to look at next... Seen some other posts about a cam synchronizer?

 

This sounds almost identical to my cam synchronizer/position sensor when it went bad around 100k. I'm not sure about diagnostics specific to it, other than a check engine code (which if I remember correctly, mine did not throw either).

If it hasn't been replaced recently, have it checked and replaced ASAP. Your oil pump is driven off the synchronizer, and if it fully fails you will lose oil pressure completely. Make sure it's replaced with a Motorcraft unit, it's not cheap but neither is a new engine. Good luck!