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2003 Ram 4.7 Rough Idle


Scotty89
03-24-2013, 11:52 AM
I have a 2003 Ram 1500 with the 4.7 L that has a rough idle at a stop light or sign. Sometimes it idles bad enough that it dies but it will restart. It doesn't set any DTC's. I have tried a new throttle position sensor and downstream O2 sensor. If i unplug the downstream O2 sensor the truck seems to run fine. Any one have any ideas?

Chris Stewart
03-24-2013, 08:14 PM
I've read where cleaning the throttle body/butterfly with some carburetor cleaner sprayed on a shop rag and wipe the parts clean working on a 5.9L

You might clean up the Idle Air Control (IAC) valve while you have things exposed.

Scotty89
03-24-2013, 11:08 PM
I've taken the IAC out and looked at it, there wasn't much of anything on it and it seemed to move easy. I tried to clean it the best i could. I opened the throttle blade and there wasn't much build up on it either.

Chris Stewart
03-25-2013, 07:29 PM
Anything improve after cleaning?

Scotty89
03-26-2013, 07:16 AM
No improvment after cleaning IAC.

Chris Stewart
03-26-2013, 06:48 PM
How many miles on this vehicle & how many since the last tune-up?

You might try going to a chain type auto parts store for a free scan to see if there are any pending codes, which don't turn on the Check Engine light.

Scotty89
03-26-2013, 07:53 PM
It has around 100K on it and my friend has owned it since May and hasn't had any issues with it til recently. I'm not for sure when the last tune up was. I have a code reader and the only code that has been resetting in the system is a code for the oil sending unit which i know it needs replaced.

Chris Stewart
03-27-2013, 07:56 PM
Have you set your scan tool for Live Data, drove the truck, stop to start the engine missing then see what the Live Data/current conditions are?
What do you think about a fuel pressure issue?

Scotty89
04-02-2013, 08:17 AM
I updated the pcm to current software level and had her drive it home. She has been driven it for a week and it is driven better. She says it sputters maybe once when she drives it and it has died only once. Still no DTC's. I havent had the chance to check fuel pressure. Has anyone seen any purge solenoid issues on these sticking open?

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