04 Explorer RPMs climb EXTREMELY SLOW

[Joscibo]

have you since figured out the problem?

Nope today was where I learned of the rpm on an incline. The idol I thought was just the way it is or a rev limiter. Any ideas as to what I am dealing with? I have 2 like new front tires and 2 rear are nearly shot. I have 4X4 Auto,4X4 high, and 4X4 low range. Is this an AWD set up? If so I think the tire diameter is off as I have discovered a wet spot around rear diff after 2 hours of driving at hwy speeds. How do I find out in the door tag if its posi unit might end up replacing rear end?

 

[yamahor]

Nope today was where I learned of the rpm on an incline. The idol I thought was just the way it is or a rev limiter. Any ideas as to what I am dealing with? I have 2 like new front tires and 2 rear are nearly shot. I have 4X4 Auto,4X4 high, and 4X4 low range. Is this an AWD set up? If so I think the tire diameter is off as I have discovered a wet spot around rear diff after 2 hours of driving at hwy speeds. How do I find out in the door tag if its posi unit might end up replacing rear end?

My diffs leak aswell.. and as for the 4x4 it will be posi when 4x4 is engaged. It will be your input seal thats leaking.... and even your covers.



I'm starting to think this just might be the way these crap ford motors are.
But your right about the rev limiter.... it comes in at 4 grand which is very low..

When and if I figure out my rev problem i'll tell you..

And as for your surge.. I would say tps malfunction, maybe on an incline it thinks its opening or stalling. But start with air delivery/throttle.


when you have no Evidence of anything being the cause just go the trial and error route.. Its what I'm now doing.

Might spend a bit of money, but ill get new parts and a reason to work on my truck.

 

[yamahor]

and no awd. it will be Rear Wheel until the 4x4 is engaged.

 

[Joscibo]

and no awd. it will be Rear Wheel until the 4x4 is engaged.

The switch is auto 4X4 which means it comes on demand when rear wheels spin. I'm wanting to change the gear lube in it perhaps change the seal to stop the leak but I'm not sure if it needs the posi additive put in the rear diff or the front for that matter as well.

 

[Joscibo]

Air filter brand new. Has the fuel filter ever been replaced?

http://www.explorerforum.com/forums/showthread.php?t=223475&highlight=slow+acceleration&page=2

This thread is what's wrong with mine! My tires are too different in size! It's causing my rpm surge!

 

[yamahor]

This thread is what's wrong with mine! My tires are too different in size! It's causing my rpm surge!

Well ill know if the rev problem is the muffler monday.

 

[keenersclan]

no power/ no shifts

hello, got a 03 explorer 4.0 with what I thought was a bad trans but now thinking other issue. idles good but seems to lack power. will not upshift unless I let way off on throttle. does this in all gears but seems to make all shifts this way but then when doing a wot downshift I seem to limit out at 3000 rpm and actually lose mph. does the same thing when climbing even a slight grade. actually goes faster up a grade if I keep my foot out of it and keep it in a higher gear at low rpm. more rpm-slower it goes but rpm maxs at 3000. no codes set. could this be a part plug exhaust? bad o2 sensor?
plan to put scanner on and record o2 readings while driving. if plugged exhaust would readings be high or low? wouldnt I have codes for o2 being rich if exhaust was backed up? could this be a pcm problem?

 

[yamahor]

hello, got a 03 explorer 4.0 with what I thought was a bad trans but now thinking other issue. idles good but seems to lack power. will not upshift unless I let way off on throttle. does this in all gears but seems to make all shifts this way but then when doing a wot downshift I seem to limit out at 3000 rpm and actually lose mph. does the same thing when climbing even a slight grade. actually goes faster up a grade if I keep my foot out of it and keep it in a higher gear at low rpm. more rpm-slower it goes but rpm maxs at 3000. no codes set. could this be a part plug exhaust? bad o2 sensor?
plan to put scanner on and record o2 readings while driving. if plugged exhaust would readings be high or low? wouldnt I have codes for o2 being rich if exhaust was backed up? could this be a pcm problem?

You'll get more responces if you start a new thread, this one is nearing its end and no one will be checking it as often.

 

[keenersclan]

solved

hello, got a 03 explorer 4.0 with what I thought was a bad trans but now thinking other issue. idles good but seems to lack power. will not upshift unless I let way off on throttle. does this in all gears but seems to make all shifts this way but then when doing a wot downshift I seem to limit out at 3000 rpm and actually lose mph. does the same thing when climbing even a slight grade. actually goes faster up a grade if I keep my foot out of it and keep it in a higher gear at low rpm. more rpm-slower it goes but rpm maxs at 3000. no codes set. could this be a part plug exhaust? bad o2 sensor?
plan to put scanner on and record o2 readings while driving. if plugged exhaust would readings be high or low? wouldnt I have codes for o2 being rich if exhaust was backed up? could this be a pcm problem?

bad downstream converter plugging exhaust