I have a 2001 3.0 automatic and at 4000 rpm it jerks almost like a rev limiter but if I'm hard on it from a dead stop I sometimes can get it past 4000 it's almost like it's trying to shift but can't get past the gear. If I let off it'll back down to 300 and I'll continue to accelerate slowly. Please help

 

You need to do some basic diagnostics.

Your problem may be a simple spark plug or wire issue.

First do you have a check engine light on?

Are there any stored codes in the computer?

Have you checked any of the basics?

Oil level and oil smell? does the oil smell normal or does it smell like raw fuel?

Coolant level is the coolant level topped off and does not leak?

Does the engine overheat and does the temperature gauge work reliably ?

 

oil is good and fresh engine not over heating temp gauge reliable coolant level good. Haven't checked for stored codes. No lights on

 

Did you smell the oil and feel it to see if it is very thin ( diluted with gas ) or are you just saying it is good because you recently changed it?

 

no it's not thin. I have checked it

 

What's in the airbox?

 

Early 2000's Ranger 3.0l's had a bad batch of Coil packs, similar symptoms as you describe
There is no way to test if a coil pack is GOOD, only if it is bad when cold

So as much as I hate "throwing parts" at something, in this cause I would get a new coil pack
There were 2 different connector designs for the 3.0l coil packs, make sure you get the correct one
And pay close attention to the Firing order easy to mess that up

 

Interesting....

Slightly related, how smooth is the 3.0 idle supposed to be? mine isn't consistent and get a reasonable amount of antenna wobble, V6's are supposed to be smooth.

 

Can of Seafoam in the gas tank once a year helps my 4.0l smooth out on idle.
Dirty injector tips cause "dripping" fuel at idle, but good spray/mix at higher RPM

Coil pack issue was more pronounced at high RPMs, didn't effect idle as far as I remember
Each coil in the pack fires once per RPM, and a good coil has enough recovery time to generate a good spark even at 6,000 fires per minute(RPM)
But if it doesn't then you get a misfire on 2 cylinders at higher RPMs

Older single coils fired 3 times per RPM, V6, 4 times for V8
So 3 coil pack is better, but can still fail, like anything else

There were "batch numbers" for the bad coils, mentioned above, but haven't seen them listed for awhile, it was a Ford TSB

 

They are quite smooth, I can barely tell mine is idling and for the most part, I can't tell. (fully warmed up) (even cold it's still pretty smooth)

 

I actually just threw some Techron concentrate in it last night, we'll see.

The smoothness of the idle is there, revs are stable, but it "shunts" for want of a better term, like it's dropping a bang cycle once every several seconds, it's enough to make the antenna jiggle a little.

 

Do you hear a bonuses that sounds like a belt chirp at idle from time to time. You could have a bad cam synchronizer that is causing the pcm to get a false knock signal causing the engine to buck severely

 

I don't, were you asking the OP? I was hoping they'd come back and let us know how this is going.

 

yes yes I do😢

 

If it is the cam sync, it's easy to fix.
Remove the sensor at the top and inspect it, if you see what looks like rust, it isn't, it's powdered bushing material.
In worst cases the bushing becomes so worn that the mechanical part of the synchronizer starts banging into the sensor.
You mat not get any codes for this until it's real bad.

 

Replace the synchronizer your problem will be solved

 

Found out it gets worse as it warms up is this related to the sensor as well or does it sound like somthing new

 

It is all from the camshaft synchronizer it makes false knock signals to the pcm and makes the engine buck.

 

Will this also cause it to eat belts up cause I'm on belt #2 now

 

Can't see how.
When the belts break, are they frayed as if the pulley's are out of alignment ?
A bad bearing may be starting to seize, so that should be checked on all the pulleys at the front.
A seizing bearing would cause a lot of noise though, one would think.

What brand of belts are you using ?

What ever is causing your belt to break, may be causing your revving problem.
It's over loading the belt.
These belts go for years with out breaking, so something is wrong for sure.

 

You need to remove the belt and make sure all the pulleys that are supposed to spin freely do just that. They shouldn't feel gritty or wobbly or that sort of thing. Make sure they are free of old belt rubber and carefully inspect each one. I've seen some that were misaligned that the edges wore to a razor sharp edge. Never use a solvent to clean a serpentine belt, especially the inexpensive ones. Solvents can break down the material the belt is made of and ruin it. "Belt Dressing" can screw them up as well. Clean, aligned pulleys and a good quality belt should last a very long time.

 

my 2003 mazda B3000 does this at about 3500 RPM. plugs, wires and coil have been changed and still a very rough idle exists. will probably pick up the cam synchro and try it

 

it is aligned. Belt is actually still good just sounds like a belt squeak. Pullys are good.

 

New question when I replace this camshaft sensor do I only need to replace the top sensor part of it or the complete setup

 

The sensor is replaced because the synchronizers bushing is shot and it allows the tooth that passes in front of the sensor to come in contact with the actual sensor.

This chews up the sensor.
If your sensor isn't damaged, then most likely it's OK and not causing any problems.
The sensor circled in red has been eaten away from a worn synchronizer.
The left screen shot shows an example of the tooth that's bent when it bangs into the sensor.

If the synchronizer is banging into the sensor, but it isn't damaged yet, then you will need to replace both.