03 ranger edge, 2wd, auto, 3.0; 6cyl. 54,000 miles. When driving, usually up grade and try to accelerate, truck bucks real bad and bogs down. already changed fuel filter and plugs. (also did oil/filter change and x-mission service). No engine codes. At normal speed runs great. Drive 75 miles one way every day, last 40 on I-75 south into Knoxville, several big hills, kinda scary not being able to accelerate around big trucks on some of those grades. any idea's?

 

might have a vac hose thats collapising when the engine is under a heavy load like pulling a big hill

 

check fuel pressure. Guage kit available at aprts store-very easy.

 

hogsfan12,

Any update on your situation? I have a 2002 Mazda B3000 (Ford Ranger), which is a 3.0L V6, that is doing the same thing. Regular daily driving is no issue, but at higher rpms (usually whenever the automatic transmission downshifts), it bucks, stalls, etc.

 

Did you replace the plug wires also, mine was doing the same thing put new plugs and wires in. Aside of my plugs needing replaced I had a bad wire, either way it solve my similar issue if you haven't changed the wires yet, you might want to look into that too.

 

Mine does the same thing, but only when I hit 90. That's when the speed limiter kicks in!!

 

I've had the same problem before, but found no solution.

 

clean or replace your IAC valve (Idler Air Valve) its on your throttle body its like a $30 part

 

I say it's the speed limiter! It kicks in at 90, I found that out on I-75 also. You gotta get a chip or tuner to get rid of the limiter!

 

+1

 

hay man having the same problem checking ignition hopefully tomorrow but i already popped out the spark plugs from the look they weren't in that bad of shape but ima test the wires, distributer and the plugs see if that fixes it. let me know if you figure anything out. good luck. and if we are havint the same problem its definitely not the speed limiter mine does it at 3500rpm about