Surging, Hesitating, Stalling?
 

I have a 2004 Pacifica, 3.5 engine with 108,000 miles on it. The car has an interment bucking/hesitating; like the gas petal is not working and then surges after pumping it several times. This happens regardless of temperature. This can happen while cruising at 50 miles an hour or just pulling out of the driveway. Sometimes while idling, or at a stop light, the engine will start to run very rough; not a miss but a fluctuation in idle speed. The idle will drops so low it sometimes stalls. I took it to a Chrysler dealership and had them check it out. They found a bad O2 sensor which they replaced. It did not fix the problem. I replaced all the spark plugs and wires, cleaned the throttle body while the upper manifold was off, and checked the silicone gasket. I ran some injector cleaner through the infectors and replaced the Throttle Position Sensor. I use only OEM parts. I pulled the Idle Air Control Motor, cleaned it, and it moved when the ignition was turned on. I also cleaned the manifold Turning Valve but I don’t know if it works. I am stuck? What else should I check?

That engine interminent hesitation/buckling is cause by a bad EGR valve. I had a similar problem. I had it replaced by a mechanic for $160.00 including the EGR valve. The vehicle has no more hesitation and its running about 24.6 mpg

Maybe more than just a EGR?
 

This just happened to me yesterday for the first time. I'm driving down the road maybe have gone maybe and mile and the gas pedal does nothing and the engine sounds like it wants to stall. Most of the time it doesn't and I just pump the gas pedal for a few minutes and then I'm okay the rest of my trip. Of course til I get back in the car to go to next desitnation and same problem all over again. Just started yesterday. Kinda scary!

Do you have a question? EGR valve you are wondering?

Hi. I am experiencing the same problem with my 2005 Chrysler Pacifica. It drives fine then out of no where it stalls and there is no power in the gas pedal. I conducted research on 2005 Chrysler Pacificas and there are tons of people out there with the same issues. There are two recalls one for the headlight and one with a fuel pump module-don't know if this is the problem. It is scary driving the car because you don't know when it will do this. My husband would get in the car and it wouldn't do anything. It is currently in the shop now and if I find out what the problem is I will let you know.

Oh by the way a Chrysler customer car rep advised us that is what we get for buying a used car when we were inquiring about the recalls.

Did u change both oxigen sensors or was it just one at the time?

Continue Searching
 

My 2004 Pacifica has a complete loss of throttle when starting out in the morning or once the car has been off for 15-20 minutes. I also have replaced a lot of components and done a lot of work trying to correct this problem, but the fix has alluded me. I have a laptop with an OBD2 connection and Digimoto software. I have an error code 02 sensor 1/1 Heater Circuit. Until I clear this error I don’t think I can move on. My understanding is that before the O2 sensor is above 600 degrees it will not produce the 0-1 volt needed by the PCM to control the fuel. Even if I let the car idle until it reaches operating temperature the car will still act like the throttle is not connected for about 10 seconds while driving. I have no control of accelerating the car until it decides to go and then lurches into acceleration. I can avoid this situation (before it happens) by shifting into neutral and raising the RPM’s of the engine to 2000 and holding it there for 20 seconds. I believe this raises the O2 sensor temperature and corrects the problem because the car drives normally after that. I can’t do this first thing in the morning because the whole exhaust system is cold but if I warm it up first or drive a little ways and then raise the RPM’s the car will work fine. If I’m in slow traffic or idle a long period of time the engine will begin it’s erratic idle and I must raise the RPM’s again or when the light turns green traffic will piles up behind me waiting for the engine to go.
The throttle position sensor (TPS) continues to work sending to the PCM the correct pedal position throughout all my test runs. Once hot the O2 sensor sends a constant varying voltage between .1 and .9. (as read by my software) but before that is at 1.2 volts and stays there. The problem happens when the fuel rails go from open loop to closed loop. My understanding is that if O2 voltage is not supplied to the PCM it will supply it itself. I think it is doing that but for some reason between the hand off from the open loop to the close loop there is a gap in O2 voltage. When this happens the PCM shuts down the fuel infectors. Once the correct voltage is supplied the engine works fine. I do not have the 5 volt heater voltage going to the O2 sensor as reported by the error code (P0031). There is a 4 prong connector connecting the upstream O2 sensor to the PCM. At that plug check the brown wire with a tan strip for 5 volts while the engine is running. The black/light green wire is the ground. My wire is not grounded but I checked it with the car off. Today I will recheck it with the car running to be sure. The manual say check out with heater circuit with the DRBIII, which I don’t have, so my checks are all with a meter. The manuals conclusion is to replace the PCM unit. I know from many other post on the internet just changing the PCM will not guarantee me a fix. I think there are other problems I’m missing. Before I go any farther I must have the O2 heater circuit working and I believe I have a grounding problem. About 2 weeks ago the passenger door started giving an interment “Door Ajar” warning. The interior lights will come on and will drain the battery if the car is shut off. If it happens while driving I have to listen to Ding, Ding, Ding, the whole trip. Several months ago the back hatch started opening up all on its own for a week.
I’ve added an extra body ground but that didn’t help. I will be removing the PCM and cleaning it making sure it is grounded today and check O2 ground. The manual tells me there are 2 grounds, a power ground and sensor ground. It looks like I need to check G101 (lower left side of engine) and G102 (left side on engine).
sseverett

That's definitely your EGR valve. I had the same symptoms and I went to the dealership and bought one and changed it myself. Took a hour to replace and drives perfect. I believe the part was around $30. Very easy to do if you have the right tools.

I had this same problem, loss of power after you take off, as soon as I shift to a neutral bring up the rpms high I could drive ok. after a drive when you put it in a park and wait a minute the car starts to rattle. I tested it and found that the o2 sensors were bad. I replaced both upstream and downstream sensors by a bosh type brand. They worked good until same problem started again. Tested it again found one sensor bad and circuit high voltage. I checked online who is the OEM for chryslers oxigen sensors and found it is Denso. So I ordered those through Autozone, replaced them and my car runners like new again.

I am having the same problem with my 100K 05 but seems like only when the Pac is cold or running for 5-10 minutes. From reading this post I am leaning to either EGR or O2 sensors but I hate throwing parts at the car hoping to fix it.

Been there...
 

I was having the problems, on a 2007 4.0 fwd, with approx 44k it would surge around 900 to 1200 rpm while driving, and just above idle in park. I was told by 1 dealer that it was carbon build up in throttle body. so I cleaned the throttle body and still same problem. I took it to dealer and thier dig was the EGR valve. which was replace under warranty. they also updated the engine managment computer. right now it seems to have cured the problem, but will drive for a few more days and repost results. but for now it sounds like you problem is a EGR valve. "IMO" hope this helps.

might want to chech cats? i know when cats start giving problems it makes u think u have a fuel system problem/what kind of codes do u have? hope this helps

Replaced the plugs last weekend and that didnt solve the problem but it does run better. I checked for codes and there are none. Next up is replacing the EGR since it didnt cost much.

Solution to Loss of Throttle
 

Solution to the loss of throttle
The Chrysler computers need a signal from the front O2 sensor to run correctly. What is happening is the O2 sensor is not putting out a signal until it is warmed. This happens after a few minutes of driving but until a correct signal is sent out by the O2 sensor, the PCM (engine computer) is on its own deciding how much fuel to inject into the engine based on your throttle position and water temperature. It has a special program to do that; it is called open loop. What is happening is the computer is going into closed loop and expecting a signal from the O2 sensor. Because of emission standards PCM’s go into closed loop as quickly as possible. To get the O2 sensor sending out a signal quickly, so it is working by the time the PCM goes into closed loop, engineers have added a heating circuit to the O2 sensor. The sensor must be above 600 degrees to output a signal and this is where the intermittent problem starts to happen. You can let the car idle in the driveway for half an hour and 90 seconds into your drive you lose your throttle. If it is the O2 heater circuit causing the problem, slide the shifter into neutral and push the throttle down. Eventually the engine RPM’s will raise (maybe 5 seconds; seems like forever) and then hold them at 2000rpm for 20 seconds. This will heat the sensor and the throttle will work correctly. If you stop at the store, or wait too long in traffic, you will need to do it again. If you notice a little hesitation the O2 sensor is too cold to work again.
There are 2 reasons for this problem.
One is your O2 heating element in the sensor is bad. To check it unplug the sensor and do an ohm reading across the 2 black wires. It should read 5 ohms. If not replace it.
Second problem; your PCM is not sending out 5 volts to the heater to heat it up. This could be a bad PCM or bad wiring. Checking the wiring harness from the PCM to the O2 sensor one will be ground and one should have 5 volts. The problem with checking it with the O2 sensor unplugged is that there is no load on the PCM and it could still read 5 volts without a load and zero with a load. Plug the sensor back in and check the voltage at the PCM. The factory manual says the heater voltage is supplied to the O2 sensor bank 1 sensor 1 through pin 18 (Black/Orange plug) C2 PCM. It is the second plug up from the bottom and has an orange strip on it. The wire is a brown wire with a tan strip. You have to pull the hood, that covers the back of the plug, off and insert a thin wire into the back of the PCM plug reaching in as far as you can. This is not as easy as it sounds so I recommend unplugging the plug and check using an ohm meter to make sure your wire has contacted the pin. Before you reinsert the plug back into the PCM check the continuity of the brown wire with tan strip to the O2 sensor plug. If the wire is good plug the plug back into the PCM. Start the car and check for 5 volts. If there is no voltage on this pin the manual say replace the PCM unit.
I wanted to make sure the PCM was causing the problem before I spent a lot of money on a new one. All you need to do is supply 5 volts to the heater so I bought a 25 watt DC/DC 12V/24V step down to 5V on Ebay for about $15 including shipping. (I think you could get by with just a 5 watt) I cut just the positive black heater wire about 8” from the sensor and connected the 5 volt wire from the step down power supply. The other 3 wires are still in place. Use an ohm meter to find which black wire is the ground and the other black wire will be the power. O2 sensors have 4 wires 1 blue, 1 white (O2 sensor voltage) and 2 black wires (power for the heater). We have not had any more problems with the throttle so why spend the money on a new PCM. Fixing it this way will keep an “Check Engine” light on all the time. I’ve thought about adding a resister to the dangling heater wire under the car but my wife has become so use to warning light on the dash (it took me a year to figure this all out) that I didn’t go to the trouble.
Before adding a different power supply make sure you remove and clean your ground wires. They are located under the battery box up front. There are 3 of them. I added an extra ground wire from the negative post to the body grounds. These cars use 5 volt for sensors and any grounding problems will cause sensor problems. A sensor problem causes the body/engine computers to do strange things.
For those who claim this is an EGR problem I have to disagree. If you have rough idle, misses on acceleration, and hesitation then EGR is your problem. Those of us who have problems with a loss of throttle, sometimes, will know exactly what I’m talking about. It is like your car is ignoring you! This is an O2 sensor problem.
What we don’t realize is that today’s cars are accelerated by computers and not us. We request to the computer to go faster by pushing on the gas pedal. The gas pedal opens up the air to the engine and by way of a Throttle Position Sensor tells the computer how fast you want to go. The computer then pulses the injectors to reach the RPM’s needed. The PCM then checks with the O2 sensor to see if there is too much or too little gasoline going into the engine. It then adjusts the fuel injector pulses to get maximum air/fuel ratio. When the O2 sensor is not outputting the correct voltage, when the PCM is in close loop, it understands the voltage to say “Too Rich; Cut back Fuel” and the short term fuel trim bank will pull back. My “Short Term Fuel Trim Bank” was at a -30% when I would lose my throttle.
I hope this helps,
steve

Having these issues only after replacing my original O2 sensors (@ 120k miles) with Bosch O2 sensors.... Had P0440 and another error for EVAP vacuum... I think we found the hose that was causing the issue (the one connected to air filter was chewy, so cut and clamped... But now these new issues of when idling either sputtering or too much gas.... Ordered NTK o2 sensors. Should be here tomorrow. Funny that I didnt have the issue until replacing with Bosch. But I also get crappy mpg... 15. So replacing those, and I will get an EGR valve to replace next month. Also just ordered a PCV valve. I can't remember when the last time I replaced that if ever, so hoping that this all will solve the problem, and give me a lot better gas mileage.

As to the fix that keeps the check engine light on, we are in VA and can't pass emissions with that on, which is a stupid yearly thing, so that's why I'm fighting all this, since the check engine light has been on since I bought the car... well soon after.

I am just hitting about 90,000 on my 05 Pacifica Touring, I've owned it less than a year and we love the car. I am experiencing intermittent surging at idle and at cruise, also have stalled a few times at low idling speeds. This is happening more now than not. The info in this thread is great. So, I will replace the EGR and the O2 sensors along with plugs and a few other tune up parts. I will replace one part at a time starting with the EGR and then both the O2 sensors. I will post which one fixed it for me. I am taking the car on a long trip with the family across a few states in a couple of months and hope this fixes my problem. Thanks again for the info!

Clean your throttle body and change the EGR first. I highly doubt your o2 sensor has gone bad. I had the same symptoms and done the very same thing with excellent results. Drives perfect all over again.

Thanks ttype, will do. Yes, I forgot to mention I did clean the throttle body already. It helped with a sticky throttle peddle. I will be adding a K&N filter also. Trying to squeeze as much fuel economy as I can out of her. I currently get about 18 MPG combined right now. I am seriously thinking of installing a Hydrogen cell also, still researching that one though.

Update:

Well, found out the issue from the p0499 I as having as well as the O2 sensors and the cause of the hesitation and/or surging... somehow my battery overheated (due to my alternator going bad or the battery - says Chrysler techs) and in doing so the battery dripped acid onto my main engine harness (the thing that runs all the sensors to the PCM) as well as getting into the wire from the purge solenoid to being carried by current to the middle of the car and the wire is broken there....

Chrysler estimates it to be @ 6k worth of work.... However, I will get the parts from somewhere else 250 @ for main engine harness (if they still have it) and 280 @ for the body harness, and then find someone else to put it in.... Because really 6k is another car.... Hope this doesn't happen to anyone else!

<UPDATE> I installed the new EGR valve first before I would tackle the O2 sensors and it fixed the problem. Car runs smooth as silk. So I'll leave the O2 sensors alone. Thanks for all the help guys!

Good day, or eve to all. M having a similar problem after changing plugs, boots and EGR. There are no codes. All plugs and hoses are good and installed correctly. Checked and rechecked plugs and hoses etc...etc... Anyone with an idea of whats going on? all input will be greatly appreciated. Thanks

05 Pacifica/ Pelum,EGR Valve
 

Well this is all new to me! After hours of investigating this issue, is there a gasket, some kind of seal between the EGR tube and the Pelum? Getting all kinds of codes that clear except for one on the maps sensor. Looks like there should be something between the two. Any input will be appreciated. Thanks

FINALLY!! After a tuneup, 05 was surging badly. Discovered a seal missing between the plenum(intake) and the EGR tube, was missing. Didnt see it when it was apart. Thus, problem solved. Now to get rid of the codes. Oh and by the way the only place I found one was at a dealership. Go figure....

I have an '07 Pacifica w/ 4.0L w/ similar issues. It starts easily, but idles very rough and runs
like it has only 3 cylinders. The car has 57K miles. Trouble codes were to replace the front
O2 sensors, which I did. Additional trouble code was to replace Intake short runner manifold
valve actuator located on the front part of the intake- but the part is on national back order for over 6 weeks.

So - we disconnected the actuator valve - this helped a little.. It seems there is another manifold actuator on the back of intake as well - should we disconnect this as well...

The car bucks and and gas mileage has decreased as well.

Any ideas......???

When last have you changed your spark plugs and air filter? That's always a good starting point, and just good general maintenance.

Thanks for all the posts here. My '05 had the characteristic hesitation off the line, then surging when steady at 25MPH, or about 37-38MPH. Finally yesterday it stalled when maneuvering at idle in a parking lot. Grabbed an EGR from O'Reilly for $32 with limited lifetime warranty. It was a bit of a bear to change. I used a combination of short/long extensions and/or deep and shallow sockets to get at the main EGR bolts (2 X 10mm). But it is in, and the car is running great. I had not had any roughness at idle that I noticed, but I can just tell overall it is running better and smoother. Prior to the EGR I had thoroughly cleaned the throttle body and idle air control seeking to solve the issue.

This is the most complete answer I have seen so far for this problem.
I am going to follow your suggestions to a T. Cept I will have my son doing the work since I am unable. I will be out there with a copy of this post and we will go over everything step by step starting with faulty grounds. Have already replaced EGR and MAP sensors.

Thank you so much for this post. Now I can be happy driving my 05 Pacifica instead of scared. :p

Eureka!!!! Problems fixed
 

Eureka!!!! Your problems are solved.. If your having shuttering problems, problems with your EGR, idle air control, throttle positioning sensor, car not turning over, car acting erratically or dying out and even transmission issues such as going in limp mode not switching gears... It is in 2 places the wire harness!!!!
1) Under the tire well above the dog bone for suspension is a Negative or ground cable bolted to the transmission this sometimes comes loose and will prevent your car from starting or even turning over.. There is also a harness that passes over this bolt which will rub out on the back side in time.. This will cause problems in the egr, i.a.c., t.p.s and Ats.... Fix the wire fix the problem
2) if you open your hood under your battery not directly but down low youll see your solenoid packs and other transmission sensors follow these to the thicker wire harness down to wear it almost touches the frame and meets other wire harnesses... The back side of this "crossroad" rubs up against some kind of flange on the transmission with bolt holes in it.. This is the problem with transmission issues in the 2004 Chrysler Pacifica 3.5l.. Fix the wire fix the problem!!! I spent alot of money on parts to figure out this simple easy cheap fix.. Make sure to reinforce protection in the back of theose wires during fix.. Hope i saved you some time and money!

Eureka!!!! Problems fixed
 

Eureka!!!! Your problems are solved.. If your having shuttering problems, problems with your EGR, idle air control, throttle positioning sensor, car not turning over, car acting erratically or dying out and even transmission issues such as going in limp mode not switching gears... It is in 2 places the wire harness!!!!
1) Under the tire well above the dog bone for suspension is a Negative or ground cable bolted to the transmission this sometimes comes loose and will prevent your car from starting or even turning over.. There is also a harness that passes over this bolt which will rub out on the back side in time.. This will cause problems in the egr, i.a.c., t.p.s and Ats.... Fix the wire fix the problem
2) if you open your hood under your battery not directly but down low youll see your solenoid packs and other transmission sensors follow these to the thicker wire harness down to wear it almost touches the frame and meets other wire harnesses... The back side of this "crossroad" rubs up against some kind of flange on the transmission with bolt holes in it.. This is the problem with transmission issues in the 2004 Chrysler Pacifica 3.5l.. Fix the wire fix the problem!!! I spent alot of money on parts to figure out this simple easy cheap fix.. Make sure to reinforce protection in the back of theose wires during fix.. Hope i save dyou some time and money

just curious, would this also cause "check engine" light to come on?:eek: