Rough engine idle

hm.. thats a tough one.... are you sure they did the tune up and cleaned everything.... all of that point to tune up.... maybe it could your timing is off or maybe a clogged cat possibly... when does the truck have the condition all the time sometimes.... hot or cold at only a certin mph?

Well they said they cleaned everything. Truck ran like a dream for about a day after tune-up. The condition is pretty much all the time. You know when you ease up on the gas pedal when you get to desired speed? Thats when it seems to do it. Hot or cold don't seem to matter. Warmer days are bad , cold days seems fine. I don't get it! I don't think it is the timing. Clogged converter? How could I tell?

It could be either of the sensors.... TPS or IAC, could even be something as simple as the PCV valve. I would put my money on the TPS, any decent shop should be able to test it for you. Check out www.Dakota-Durango.com, a lot of knowledgeable people over there if you have any other questions. BTW how did you manage to spend 600 bucks on a tune up?

The 3.9L engine does have a weird idle quality to it. However, it sounds like your problem may be related to a TPS or even an oxygen sensor misreading under load. It may not be enough to throw a code but it might cause the "chuggle" you're experiencing. Also look into the ignition module as a possible cause.

I a simmilar problem my truck wont idle down, if I stop at a stop light my motor will rev at the same RPM I was crusing at it's very annoying I replaced the IAC with no luck. It happens when I have the AC on or if im towing my trailer. Im not sure what the next step is.

i agree, sound like tps sensor, if the speed is above say 35 or so and the truck gets into 4th gear the lock torque converter sound like it locking and unlocking due to false reading of the tps, this can happen in 3rg gear also.. try driving at a steady 50pmh with no load on the engine, just enough to maintain 50, if its seems like it drops 2-300 rpm on the tach and then goes back up, id bet money the tps is it..

I changed the TPS now truck is running awsome. Thanks!

JAY, I'M NOT AN EXPERT OR A MECHANIC, BUT...I'VE BEEN WORKING ON AUTOS FOR OVER 50 YRS. I PREFER THE PRE '70'S. THE MOPAR VEHICLES HAVE OBD'S=ON BOARD DIAGNOSTICS CHECKED WITH THE IGNITION. I AM A MOPAR MAN & I SUGGEST THAT YOU GO TO YOUR TRUCK...TURN IGNITION KEY TO "ON"-NOT START-OFF...ON...OFF...ON. AFTER THE 3rd ON CYCLE...WATCH THE DASH. WITH A PEN...WRITE THE DTC/DTC'S THAT WILL BE DISPLAYED IN A CYCLE-USUALLY A CHECK ENGINE LIGHT OR SIMILAR LIGHT. IT WILL FLASH 1 TIME...THEN 2 TIMES...1 TIME...2 TIMES-12 CODE IS THE CODE FOR EMC POWER INTERRUPTION CODE. THE NEXT FLASHES... COUNT. i.e.: 2 FLASHES...PAUSE...4 FLASHES...PAUSE...5 FLASHES...PAUSE...5 FLASHES=55 CODE=END OF DTC CHECK. THE ECM TELLS YOU THERE IS A "24" DTC . THIS CODE MEANS TO CHECK THE TPS=THROTTLE POSITION SENSOR. OTHER CODES DISPLAYED WILL REQUIRE YOU TO CHECK A DTC LIST FOR YOUR TRUCK. I HOPE THIS HAS HELPED. DOING THIS WILL SAVE YOU A TON OF $$$$. I JUST WISHED YOU HAD THIS INFOR BEFORE YOU SPENT $600 ON A "TUNEUP" FOR 1 DAY OF TROUBLE FREE DRIVING.

can someone tell me where the tps is located and how hard is it to change

THE TPS...THROTTLE POSITION SENSOR...IS LOCATED ON THE DRIVER'S SIDE OF THE THROTTLE BODY-NATURALLY ASPIRATED-ENGINES IN THE '92 DAKOTA V-6. PULL OFF THE AIR CLEANER HOUSING...SET ASIDE...LOOK AT THE TH-BODY. THE TPS IS ATTACHED AT THE END OF THE THROTTLE SHAFT OF THE T-B. IT IS PART OF AN OVAL/ROUND SHAPED "PROTRUSION" OUT FROM THE T-B-STICKING OUT ABOUT 1". THE TPS IS ATTACHED TO IT WITH 2 TORX SCREWS. IT IS ABOUT 1-1/2" IN WIDTH WITH THE MALE CONNECTOR REMOVED. BE SURE TO DISCONNECT THE NEG TERMINAL WHEN REMOVING CONNECTOR TO PREVENT AN ACCIDENTAL SPARK THAT MAY IGNITE ANY "POOLED" GASOLINE.

I'M NOT A PRO MECH BUT...I JUST HAD PROBLEMS WITH A BAD "IAC"-IDLE AIR CONTROL VALVE & THAT'S HOW MY DAKOTA ACTED FROM TIME TO TIME-GENERALLY AT ACCELERATION BUT, SMOOTHED OUT @ 60mph. THE IAC HAS A "PENTIL" THAT MOVES BACK & FORTH-WHEN ENERGIZED-GETTING A SIGNAL FROM THE TPS THRU THE ECM. AT IDLE THE PENTIL STAYS IN TO RESTRICT AIR FLOW. AS THE TPS MOVES OPEN...SO DOES THE PENTIL OPEN UP ALLOWING A "FREE-FLOW" OF AIR THROUGH THE AIRHORN. THE CAT CONV'R-IF "RESTRICTING"-WILL CAUSE THE ENGINE TO BACK UP IN PRESSURE-PREVENTING THE FREE EXHAUST FLOW-SLOWING THE RPMS DOWN. AS THE RESTRICTION "LIFTS"-OPENS UP-SO WILL THE RPM'S.

To the guy that wrote this..... "JAY, I'M NOT AN EXPERT OR A MECHANIC, BUT...I'VE BEEN WORKING ON AUTOS FOR OVER 50 YRS. I PREFER THE PRE '70'S. THE MOPAR VEHICLES HAVE OBD'S=ON BOARD DIAGNOSTICS CHECKED WITH THE IGNITION. I AM A MOPAR MAN & I SUGGEST THAT YOU GO TO YOUR TRUCK...TURN IGNITION KEY TO "ON"-NOT START-OFF...ON...OFF...ON. AFTER THE 3rd ON CYCLE...WATCH THE DASH. WITH A PEN...WRITE THE DTC/DTC'S THAT WILL BE DISPLAYED IN A CYCLE-USUALLY A CHECK ENGINE LIGHT OR SIMILAR LIGHT. IT WILL FLASH 1 TIME...THEN 2 TIMES...1 TIME...2 TIMES-12 CODE IS THE CODE FOR EMC POWER INTERRUPTION CODE. THE NEXT FLASHES... COUNT. i.e.: 2 FLASHES...PAUSE...4 FLASHES...PAUSE...5 FLASHES...PAUSE...5 FLASHES=55 CODE=END OF DTC CHECK. THE ECM TELLS YOU THERE IS A "24" DTC . THIS CODE MEANS TO CHECK THE TPS=THROTTLE POSITION SENSOR. OTHER CODES DISPLAYED WILL REQUIRE YOU TO CHECK A DTC LIST FOR YOUR TRUCK. I HOPE THIS HAS HELPED. DOING THIS WILL SAVE YOU A TON OF $$$$. I JUST WISHED YOU HAD THIS INFOR BEFORE YOU SPENT $600 ON A "TUNEUP" FOR 1 DAY OF TROUBLE FREE DRIVING. " First of all..... every vehicle since the late 80's has had an OBD system not just mopars, in fact I believe it was mandatory by 1991. Only 2000 and up Dakotas have the key trick to read DTC which you mentioned... The odometer flashing is only used on OBDI vehicles (95 and earlier). On OBDII vehicles the codes are listed as a PXXXXX number

I WILL DISAGREE WITH YOU ON "Only 2000 and up Dakotas have the key trick to read DTC which you mentioned... ". I HAVE AN '87 DAYTONA & A '92 DAKOTA. BOTH WILL SHOW OBD CODES WITH THE "KEY TRICK" METHOD. THE FLASHING WILL BE DISPLAYED VIA "DTC/DTC'S THAT WILL BE DISPLAYED IN A CYCLE-USUALLY A CHECK ENGINE LIGHT OR SIMILAR LIGHT." AS MENTIONED IN MY RESPONSE-NOT AN ODOMETER LIGHT FLASHING. WITH ALL OBDII VEHICLES...YOU WILL NEED A CODE READER...THAT WILL GIVE YOU THE APPROPRIATE "P" CODE. I "AM" AWARE OF THIS PROCEDURE. THANX

You do not need a code reader for all OBDII vehicles.... as I mentioned 2000 and up Dakotas (and many other vehicles) use the same key trick to display the codes on the digital odometer screen. I did not mean to say odometer flashing for OBDI vehicles, it is the CEL that flashes. I know for a fact the key trick does not work on 97-98 and 99 Dakotas/Durangos, disagree all you want. I can not speak with any certainty on anything older than that. If you are aware of the procedure you did a poor job explaining it. This thread was about a 2001 Dakota, so the OBDI procedures are completely irrelevant. Also if you bring your attention to the left side of your keyboard, just above the "Shift" key... there is a button marked "Caps Lock", do everyone a favour and push it

THANX FOR YOUR UPDATE. THANX FOR YOUR ADVICE ON "CAPS". I REALIZE THAT "CAPS" IS RELATED TO "SHOUTING" ON THE I-NET. WHAT I DON'T UNDERSTAND...WITH THE "PURISTS" ON THE I-NET...IS THE DIFFERENCE WITH "CAPITAL ENGLISH" & "LOWER-CASE ENGLISH". ENGLISH IS ENGLISH. ADVERTISING...LABELING...SIGN POSTS...INTERSTATE ROAD SIGNS...ROAD SIGNS...AUTO BADGES...CREDIT CARDS...DRIVER'S LICENSES...& PRODUCT BADGES ARE ALL IN CAPS........WHERE'S THE PROBLEM?! THE ONLY "SHOUTING" I SEE IS WHAT SPORTS FANS & HUSBANDS & WIVES DO. BEEN DOING IT SINCE 1994. DON'T THINK PUSHING THE "CAP" KEY IS DOING ANYONE A FAVOR...JUST GIVING "CONTROL" TO THOSE WHO THINK THEY NEED IT.

I have a 2005 Nissan maxima, i think am having the same problem . Can it also be the Tps on my car?

i, have a 96 dakota with a 3.9 and it idles fine when cold, once it warms up it wont idle at all! runs great just wont idle, it shuts off! i bought a iac and put it in and it idled about 3000 rpm how do you set these?????

I have logged 93,000 on my 2002 Dodge Dakota Quad Cab Plus 3.9 V6 since i bought the truck from the original owner. it now has 139,000 miles. One month ago the engine got to where it would not idle unless i kept my foot on the gas petal. I bought the best spark plugs available and a new Idle Air Control Valve (IAC) and took them to my New Car Dealer and had the engine professionally tuned up and the throttle body fuel injectors flushed and cleaned. $340 and now the truck runs great and has a lot more power. It has been one month since the dealer tuned it up and i could not be happier with the performance of my 13 year old truck.

I own a 2003 Dak 3.9 v6, manual trans. It was slowing down and missing specially on the highway. After a tune-up and an ignition coil replacement the problem was still present. I replaced the crank position sensor and is running fine now. However it's idling a little rough.

If your truck has a MAF mass air flow sensor vs. a MAP manifold absolute pressure sensor all you need to do is get the MAF sensor cleaner, the wire sensor gets a patina after about 100k miles and can work intermittently causing stuttering because of misfire even though the computer does not register any fault codes. Had the same issues with my 02 ranger, Did not even need to replace the sensor which is not cheap, maybe $10 for the spray cleaner looks like carb cleaner but designed to safely clean the MAF wire.

I know this is a little late but the TPS is located one the passenger side of the throttle body of the 1990 3.9L V6 right under the MAP sensor........

I e got a 2002 dakota and I've replaced everything electronic and it still runs rough and is really hard to start

I have a 2002 dodge dakota it's very hard to start in the mornings and it misses and idles ruff just at low rim I've replaced everything electrical new throttle body does anyone know what it might be

Sell it and buy a different make of vehicle like I did. I dumped my Dakota, too many problems developing all at once.

I have a 2002 dodge Dakota sportanf after replacing water pump it started acting like this but it doesn't idle it cuts off and

It also backfires and acts like its getting no gas

What if the box to read codes don't work

Anyone with a Chrysler/Dodge/Ram/Jeep etc from 1996 1997 1998 1999 etc with the jtec style computer (the same ones in the '98 Dodge Dakota), there is a simple solution to the random rough idle and stalling issues. Remove the left torx screw on the PCM computer, add two washers and then replace the screw. Can do the same with the other side, but do them one at a time. The screw seems to be just long enough to eventually ground out a component inside the computer and cause the engine to stall out. Didn't believe it myself, but when I pressed on the screw there in the front the engine died and backing the screw out fixed the issue. On warm days or once the engine was warmed up, the thermal expansion must have been just enough to momentarily ground the component.

Really, your answer was spot on for my 99 Dakota 3.6L. Had idle problems, start problems (no spark) and these were all intermittent. I wiggled the connectors and it would either kil the engine or keep it running if idle was struggling. One time it turned over w/o spark, until I pushed in on the connectors while someone else turned it over. Thought I had bad harness or bad PCM, until I came across your reply and tried your recommendation on the torx screws. Problem solved. Glad you posted b/c you're the only to mention this as a problem.

**98 Dakota

Glad to hear it. Took me 6 months, lots of parts and many Google searches but I came across an obscure forum somewhere after page 14 or 17 of a Google search and one post mentioned something about a screw in the PCM grounding a component. Can't even find it again but after investigating and fixing the screw I just decided to post the information everywhere I could so it would be easier for anyone else with the same problem to find. Cheers ;)

My 2003 Dakota ran very rough. I used Lukas fuel injector cleaner which solved 90% of problem but the remaining 10% is still irritating. Is the consensus that I should get the TPS changed? I should note that previously the idle would stick.

I have an 03 Dakota that stutters during idle. I changed out the plugs, wires, cap and rotor, air filter, TPS, ICA and some injector cleaner but still no change in idle. I’m lost with this thing.

HAVE YOU CHECKED THE FUEL FILTER?? believe it or not...when those nasty li'l critters get gunked up...they play havoc on IDLE & performance-even when on CRUISE!!!! when the fuel flow/fuel pressure IS INTERUPTED....you've got problems!!!!

Can someone plz help me with this dang truck I’ve replaced the fuel pump the plugs and the ignition coil and it still has a delay start and wants to die every chance it gets it’s a 1998 3.9 v6 magnum and I’m lost

Anyone try temp sensor? I had a 92 chevy 5.7 manual 5 speed. Doing all that’s been described. I thought about it after changing everything under the sun. It controls the fuel mix when cold. Turns the choke on... just a thought.