Grand Caravan: 3.3 V6, 124,485 km or 77,352 miles

This problem started last summer, and was not present during the cold winter months. It began again this summer. I took the van into the dealer for a tune-up which included:

-new plugs & wires, clean throttle body
Problem still persists

I took it into a service station the following week to have the EGR valve checked out, and was told my car did not have an EGR valve. They did a reading from the Service Engine Light being on, and found these codes:

P1682 (Charging system voltage low)
P0203 (Inj. 3 control circuit fires improperly)
P0303 (Cyl. #3 misfire)

This mechanic, said he found that while cylinder 3 was misfiring, the spark was still present (I assume to mean normal spark).

The mechanic wanted me to try adding a cleaner to my fuel to see if the injector was perhaps in need of cleaning:

I have added injector cleaner to one fill-up and just added the 2nd batch so far.
Problem still persists

I have since made observations that this misfiring only happens when the engine is warmed-up. When I start out in the morning it works perfectly normal --once the temp. gauge hits the middle line it starts the sputtering.

When I start away from a stop the van sputters badly. It has never stalled doing this but feels like it could.

I made a highway test last weekend, for about a 1 hour route, and it worked fine while at highway speed. Only started sputtering when I drove through a town (or at city speeds)

It really looks as if the heat of the engine certainly has an affect on this problem and I'm hoping that someone can reason it out for me.

Any help would really be appreciated.

Many thanks,

--Rob

 

I'd change out the air intake temp sensor, and the coolant temp sensor.
You didn't say what year your GCV is.
If your van has two coolant temp sensors, one is for the gauge, the other for the PCM.

It sound like the PCM is getting bad input when at operating temp.

A bad O2 sensor could also cause these types of symptoms.


Hope that helps,
PinCup

 

misread and deleted my post....

 

charging system voltage low should point to alternator and/or battery. autozone will test for free and tell you. you might very well find the other problems disappear after that gets fixed....

 

Thx for reply... The battery is only a few months old, and I know for absolute certainty that the problem concerns only one cylinder (#3). I also know from the last attempt to fix problem that there is spark going to that cylinder because the mechanic tested for it. The fuel injectors were replace a little over a year ago.

I would think if the charging system was malfunctioning I'd see other signs like dim headlights when night driving, hard to crank over (starts on first click of key turn) and it would possibly affect all cylinders.

I'm booked in for another attempt to fix problem tomorrow, where the injector will be changed, and if that doesn't do it, then it sounds like the it might be the PCM itself, but that was replaced under a Chrysler recall about 2 yrs. ago.

I had the van out this morning, and the power loss was so bad it was embarrassing pulling away from intersections. Felt like it wouldn't get across the street. Today the humidity is high with a very hot outside temperature --- heat is a big part of the problem.

--Rob

 

if the charging system is low, that points to the alternator. if the alternator is going bad and not putting out enough voltage, you will have electrical problems. that is also on the list of drivability problems from the service manual. you might not notice the headlights being dimmer than usual, but the sensitive pcm will not function as intended. Autozone does this test for free and you already have that code. they will tell you if it is a bad battery or a bad alternator or both. Cyl 3 misfire may be a manifestation of that since the coils get their juice from that very same charging system. mechanic saw spark, but how can he know if it is 20,000 volts firing or 5,000? you might even do a simple test by yourself and take a multimeter and check battery voltage at the battery posts with the vehicle off and again with the vehicle on. battery voltage should be around 14 volts with the engine on. but autozone will do it for you for free.

 

This maybe getting old, But ck the injector wire harness on the rear head. You may need to open the harness up and ck the wires, they maybe melted together.

 

Im having a similar problem with 01 T&C 3.3. only my misfire isnt isolated. throws p0300 on key dance. any help would be appriciated. ive changes bank1sensor1 O2. Coukd oack is 3 months old. Cleaned throttle body and IAC. Replaced fuel filter. Swapped out MAP from a know good for testing. No improvement. drives grwat cold. And drove well with MAP unplugged. TPS being dropped by ups today. what am i missi g and how do i test it. thanks my arms tires from Throwing parts at this heap.

 

A good scanner will tell you which cylinders are misfiring. Have you changed plugs and wires? Checked vacuum output and for leaks around the intake gasket and hoses? Check injectors and injector drivers

There's several good YouTube videos on the subject.

http://www.obd-codes.com/p0300
http://repairpal.com/OBD-II-Code-P0300