Stumble/hesitation in 01 Town and Country
 

Hi I'm new here and this seems like a great site-- I'm hoping you guys can help me out.

My wife has an 01 Town & Country with the 3.8l engine. It has a stumble/hesitation that we've been able to live with, but I'd like to get rid of it. At idle with the engine warmed up after driving a while (like at a stop light), the engine will seem to miss randomly- enough to give the car a single shake every 10-20 seconds or so. It doesn't always do this. Sometimes, while accelerating from the stop light or, worse, in a left turn with on coming traffic, the van will hesitate during the acceleration. There are never any symptoms when the van is at speed.

I'm not a professional mechanic, but I have a DRBIII scan tool I picked up at an auction and have been using it to work this problem (and trying to learn along the way). There are no codes. Here's what I've done so far: replaced the spark plugs and wires with new ones, flashed the PCM and TCM to the latest software versions, cleaned the IAC, checked operation of the IAC with scan tool actuator test, replaced the TPS (per a TSB on the subject), used the scope to check the cam and crank position sensors (both seem good with correct pattern and no drop-out), checked fuel pressure and checked the MAP sensor with the scope.

Before I throw more parts and labor at this project, I'd like to be able to diagnose the problem. Here are the "issues" I've found, though I'm not sure where to go next in terms of repair:

1) Fuel pressure with the key on, engine off is 58psi which is exactly the spec. With the engine at idle, fuel pressure goes up to about 70psi, which seems high (but maybe not?). The long term fuel trim seems to be compensating at about negative 8-10%.

2) At idle, the scope shows the MAP sensor dropping about 1volt every few seconds. (I could hook up the scope again and get more precise if that would help-- unfortunately the DRBIII doesn't seem to have a good record function for this though.) I don't have the experience to know if this is normal. The MAP pressure reading at key on, engine off is the same as on my 99 Durango, so no problems there.

Of course, I have not been able to get the van to misbehave while I have the diagnostic equipment attached.


Sorry for the long first post, but you guys seem to know what you're talking about, so I'd really appreciate your help.

RE: Stumble/hesitation in 01 Town and Country
 

70 psi sounds high.read this..does this engine have egr valve??moe
OPERATION
The fuel system uses a nonadjustable pressure regulator that maintains fuel system pressure at approximately 400 ±34 kPa (58 ±5 psi). The fuel pressure regulator contains a diaphragm, calibrated spring and a fuel return valve. The spring pushes down on the diaphragm and closes off the fuel return port. System fuel pressure reflects the amount of fuel pressure required to open the return port.
The pressure regulator is a mechanical device that is NOT controlled by the PCM or engine vacuum.

RE: Stumble/hesitation in 01 Town and Country
 

Do you think the fuel pressure would cause the problem?

It does have an EGR and I removed it and checked it with a hand-vacuum pump and cleaned it up a bit. It opens and closes smoothly and holds just fine (it wasn't sticking before cleaning either). I'm not sure how I would check if there's something wrong with its control though. Is that a possibility?

Does my MAP scope pattern sound normal?-- is it normal for it to spike down a volt or so every few seconds while at idle?

I'm taking this as a chance to learn-- not just to get this fixed--and I really appreciate the help!

RE: Stumble/hesitation in 01 Town and Country
 

Rick I have a 02' 3.8l V6 town and country and I have the same hesitation problem...
The codes that I was able to get were showing 5 transmission codes or problems and the first two codes were for the first and second gears.... now I havent had a chance to get a pro. tech to check it out yet, but it feels like the transnmission to me... hope this give you a different direction and mabey you will find an answer to help me as well.
Good Luck

Acceleration Issue
 

Hey Guys....I am having the same issue. When at a stop light or just coming out of the drive way in reverse. When I shift it to Drive, remove my foot from the brake and then hit the acceleration pedal, I get a delay and then the van goes. Same at a stop light, foot on the pedal to go on green and there is a skip or delay but once the fan is going in motion on on the highway, there are no issues.

Let me know was solves this, I have done new plugs and wires and this did not solves the problem. I have lived with this so far but my wife is getting annoyed........

Thanks, Matt

Hesitation
 

My 01 T&C w/3.8 was having hesitation problems for a couple of years. Most noticeable when between 25 and 65 mph. I currently have 144,000 miles. No codes. Changed plugs and wires. Changed throttle pos. sensor. Cleaned IAC. Finally saw a fix tip to check the EGR. I disconnected the vac hose and the van ran fine. Replaced the EGR and all is well. The engine has used oil since purchased used. The intake is oily, so my guess is one of the front cylinders is sending oily exhaust gas through the EGR, and eventually made the EGR valve not seat completely.
Roger

Hi guys, I have a '01 T & C that I use to tow our family pop up camper. Recently the van started to miss similar to what I've read above. Basically around 1500 rpm's it has a slight miss which seems to be getting worse. Tonight I held on the brake and gave it some throttle to get the rpm's up to where it misses and it did. I replaced the plugs and wire with nothing getting better. Anyone find a fix for this?

Sorry, it's a 3.3 v-6. I ran some injector cleaner through and it did nothing. It also kind of dies for a split second when I'm starting out. Years ago I owned a few escorts that did exactly the same thing. When driving on a flat road it would be okay but if the grade increased slightly and I compensated with a little more throttle it would miss the same way.

Just spit-balling here. I'm no mechanic but do remember the escort miss.