2004 Dodge Ram 1500 - rough idle & stalling

[turbodan]

I have a 2004 Dodge ram 1500 4x4 5.7 Hemi automtaic 110k miles.

i noticed it has a rough idle but no check engine light (600 rpm). the spark plugs look like new. i tired unplugging each coil 1 at a time to see if one was bad but it has 2 plugs per cylinder and doesnt care if the coil is unplugged (still runs). so with a spare spark plug i checked the coils individualy and they all had spark. so i tried unpluging each fuel injector 1 at a time and each one made it run worse. so im sure it doesnt have just one bad cylinder. some kind of missfire?

Today on a cold start the engine was surging up to 1500rpm and had the throttle control light iluminated on the dash. then the truck went into limp mode when i was driving. i shut it off and started it back up and it ran fine.

also 1 week ago the truck died while stopped at a red light. it restarted fine.

any ideas what is wrong?

[taank]

Step 1: scan for codes.
Step 2: do nothing until step 1 is done.
Step 3: do step 2.

[DNeinstadt]

Clean/diagnose/replace Idle Air Control Sensor/valve/motor.

[DNeinstadt]

Also Google search:

http://dodgeforum.com/forum/3rd-gen-ram-tech/147302-2004-dodge-ram-stalling.html

Shows maybe a bad EGR

http://autoforum.classifieds1000.com/Dodge-1500_Pickup/2004_Dodge_Ram_stalls_at_idle_Has_DTC_P0406_ex_sensor

Also seeing issues resolved with cleaning the throttle body, having the transmission checked (apparently 2004 had issues), o2 sensors, etc.

[tim]

The early Hemis had valve spring issues which could explain the rough idle. They are picky about plugs but you checked that. Probably something to do with the electric throttle body.

[Beavnasty]

Step 1: scan for codes.
Step 2: do nothing until step 1 is done.
Step 3: do step 2.

This. Sometimes it will have pending codes/stored codes without a light.

[turbodan]

Step 1: scan for codes.
Step 2: do nothing until step 1 is done.
Step 3: do step 2.

i never had any codes from the rough idle when i checked in the past. (actualy rough idle isnt that bad just something ive noticed. more of a missfire)

but when it started and died in the cold it had 3 codes all to do with the throttle body, voltage limit, rpm limit. im thinking it is freezing up for some reason. if i shut it off and let it sit for 2 minutes it will restart and run fine.

i cleaned the throttle body today and notice a lot of moisture in the intake and i have also noticed condensation on the oil filler cap. (i didnt get any water or coolant out in the oil last time i changed the oil and not using any antifreeze)

good info on the valve springs i will have to check that when i have more time.

i have searched on the ram forum and found all the talk about EGR and trans fluid level. i dont think it has a IAC becasue it is drive by wire.

lots of sensors $$$ i could start replacing but would like to get an idea first if anyone knows for sure?

[iamtheshaner]

Condensation is from short run cycles. Valve coking is another result of short cycles and may be related. Diagnose the throttle body, any fault with desired throttle position can result in torque truncation so it may be the pcm killing cylinders and thus your rough idle. Figure out etc first

[RyanM]

We have done a few valve springs on these motors but they come in with missfire codes

[tim]

The moisture on the oil cap is on all of them, not just short run cycle vehicles. I drove a lot of highway miles and very very rarely short cycled and I still had it.