2004 ranger 4.0 RPM issue with clutch depressed

[jeffrey1]

Just bought my son a 2004 ranger with a 4.0 V6. Drove it 50 miles home at approx. 3000 rpm/75 mph. When I press the clutch to downshift, the rpm remains at 3000 or a little above due to no load. As I down shift but do not let clutch out the RPM slowly goes down. When almost at a stop and in first gear, the idle then returns to approx. 800. Where should I start looking to fix this. Does this sound like a sticky throttle cable/pedal or am I heading into electronics. Any help would be a good start. Thanks

 

[naford]

I think if it's what your talking about is that the rpm stays up for 2 reasons. The first was for emissions and the other was that it makes the upshifts and downshifts less jerky.

 

[jeffrey1]

Thanks for the input but what is real annoying is when I take my foot off of the accelerator and do not push in the clutch, the vehicle does not begin deceleration for a few seconds. I am used to using engine compression for the initial slow down prior to stopping. Is there anything I can do to reduce this delay?

 

[alwaysFlOoReD]

Welcome to TRS.
I don't have a quick answer for you but I did a search and came up with a bunch of threads. They might help point you in the right direction.
Search parameters I used - "high rpms clutch".
The search button is at the upper right of the page and there is also a tech section up top.

http://www.therangerstation.com/forums/showthread.php?t=135927&highlight=high+rpms+clutch

http://www.therangerstation.com/forums/showthread.php?t=76701&highlight=high+rpms+clutch

http://www.therangerstation.com/forums/showthread.php?t=69704&highlight=high+rpms+clutch

http://www.therangerstation.com/forums/showthread.php?t=97120&highlight=high+rpms+clutch

http://www.therangerstation.com/forums/showthread.php?t=103558&highlight=high+rpms+clutch

Good luck,

Richard

 

[RonD]

The Throttle Position Sensor(TPS) tells the computer when your foot is on the gas or off the gas.
http://www.therangerstation.com/Magazine/winter2009/throttle_position_sensor.htm

Or you could have a sticky throttle plate, there is a spring that holds the plate closed, if it is weak/broken the suction at higher RPM may be holding the plate open briefly, the TPS gets it info from the plate position so RPMs would be maintained.
You should be able to manually move and inspect the throttle plate to see if it is sticking or has a weak return to closed position.

 

[Earl43P]

It actually sounds like normal operation to me.

If it maintains rpms in the 1100-1300 rpm range while rolling and then drops to 800 at nearly stopped, (clutch pressed) that is normal. If it is staying higher up than that in rpms then I would suspect that the upper and lower intake manifold seals are leaking (or some other vacuum leak), which is very common on the 4.0 of all years. Eventually, the Check Engine light will come on and flag two typical codes, P0171 and P0174 if that is the case.

First thing I suggest is to remove and clean the IAC on the throttle body/intake. You'll see that a plunger on a shaft does the air modulating. Once the shaft is clean and wet with carb cleaner, whack the IAC against your palm such that the plunger is forced to slide along the shaft. It should make a thwock sound each time you whack it on your palm.

After that cleaning, reinstall the IAC and reset your computer to force it to relearn its idle strategy. Simply disconnect the - Battery terminal, turn on/off the headlamps and reconnect battery.

Start it without touching the gas. Let it idle in Park or neutral for about 4 min., then again in D with your foot on the brake. Then repeat both those steps with the air conditioner/defroster selected on. If it's a stick shift, it only needs to learn neutral and neutral with AC on.

 

[jeffrey1]

Thanks for all of the input. Looks like everyone has given me a few things to look for this weekend. The weekends fill up so fast. I will post if any of this fixes it or if it is bad at all. Once again thanks.