07 pacifica 3.8 eng. with 4 speed At low rpm's 1200 to 2000 it shudders and has a jerky feeling. It runs great at 70 mph at 2200 rpm and has good floor board acceleration . 4 dealers fail to acknowledge the problem .In neutral or park,it is almost impossible to raise the rpm's from the idle speed of 800, to any rpm less than 2200 . A few times I was able to get it to 1500 but then it dropped to idle for a few seconds then went up to 2000 a few seconde then down to 1000 then up to 2100 then down again and never move the accelerator. 3 Chrysler mechanics could not give me an answer for this. 1 service writer said it was due to the over rev limiter ,I am not that dumb. HELP PLEASE

Sounds like you might have an obstruction on one of the low speed jets. I would have the carburetors rebuilt.

Check out related help links to troubleshoot these problem:----Click the link below:---Idles Fine but RPM jumps in drive mode? http://technoanswers.blogspot.in/2012/07/idles-fine-but-rpm-jumps-in-drive-mode.html
---------Mitsubishi Lancer rpm needle bounces? http://technoanswers.blogspot.in/2012/02/mitsubishi-lancer-rpm-needle-bounces.html
--------How to adjust rpm on 2009 dodge charger SRT8?

http://schematicsdiagram.blogspot.com/2011/12/how-to-adjust-rpm-on-2009-dodge-charger.html
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Engine cuts out at 3000 RPM? http://schematicsdiagram.blogspot.com/2011/12/engine-cuts-out-at-3000-rpm.html

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Cold start problem and vehicle shudder around 2500 to 3500 rpms
http://repairhelpcenter.blogspot.com/2012/10/cold-start-problem-and-vehicle-shudder.html

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High rpm in neutral? Inconsistant high RPM in neutral? http://technoanswers.blogspot.in/2012/02/high-rpm-in-neutral-inconsistant-high.html

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Jetski Sputters and Low RPM? http://whatisbyme.blogspot.in/2012/07/jetski-sputters-and-low-rpm.html

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Fuel Injection Problem And RPM suddenly increases http://whatisbyme.blogspot.in/2012/07/fuel-injection-problem-and-rpm-suddenly.html

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2005 Toyota Highlander: Engine runs hard RPM below 3000? http://whatisbyme.blogspot.in/2012/05/2005-toyota-highlander-engine-runs-hard.html

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1987 Toyota Camry: RPM Drops going Up hills? http://whatisbyme.blogspot.in/2012/05/1987-toyota-camry-rpm-drops-going-up.html

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Cruise Control stops working, Excessive cranks to start the engine and RPM goes max 2500 http://whoisbyme.blogspot.in/2012/07/cruise-control-stops-workingexcessive.html

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1990 Toyota 4Runner: Engine cuts off when reaches 2000 RPM?

http://whatisbyme.blogspot.in/2012/05/1990-toyota-4runner-engine-cuts-off.html

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1999 Toyota Camry: Erratic stalling and high engine RPM at idle?

http://whatisbyme.blogspot.in/2012/05/1999-toyota-camry-erratic-stalling-and.html

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1995 Toyota LS: Misfire at idle or low RPM http://whatisbyme.blogspot.in/2012/04/1995-toyota-ls-misfire-at-idle-or-low.html

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Lexus RX: Tapping noise under Valve Cover At Low RPM? http://technoanswers.blogspot.in/2012/04/lexus-rx-tapping-noise-under-valve.html

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These will help.
Thanks.

Do you notice does the problem seem to worsen in rain or humid weather? Try checking the MAF sensor it may just need to cleaned it can cause problems like this. Be sure to use MAF cleaner nothing else. The sensor may also be bad but try cleaning it first, its cheap and only takes about ten minutes.

If it only happens in one particular speed/RPM then I would be looking into TPS throttle position sensor. Please check and spray carb cleaner on the MAF mass air flow sensor only.

Hi

It does look like you have a 3 speed C6, if the PRND21 description is correct. If you do have overdrive, the "D" will be printed in a white oval.

Sounds like it is OK. My Mustang has a 351C with a C6 trans, and 3000 rpm is about right at 70mph.

The defining factor on the rpm will be the Differential gears, which in a truck, might very well be taller gears instead of highway gears, as the taller gears provide more power output at the axles than the highway gears do.

Example:
if you had 3.0 to 1 gears (Highway), that means that the driveshaft will turn 3 times for every complete revolution of the rear wheels(Axle)

If you had 4.0 to 1 gears, then the driveshaft would turn 4 times for every revolution if the axle. Lots of torque for pulling stumps, but on the highway. the engine will have to turn more rpm's to maintain 70 mph vs a 3 to 1.

with the 3 to 1, you will turn less rpm's on the highway, but will have less available low speed power (Torque) at the wheels.

Sounds like the truck is doing fine.

check fuel pump or fuel filters. Check exchaust if stopped up will cause jerkying

Cruising speed rpm should be roughly 2200 rpm If OD (lockup) is not engaging it will be running at about 3,000rpm.
If it was staying engaged, you would not have a problem at cruising speed but would be "lugging" when taking off from a standstill. OD should come on at about 45mph and the tach should show a drop in rpm.

You should verify you have proper fuel pressure. Check with a gauge when cold and hot. Possible clogged fuel filter is not allowing enough gas to feed engine. Verify pressure at idle and also under load when driving.

always start with the basics,fuel filter,sparkplugs,air filter

Sounds like it could be a Throttle Position Sensor.