Posted By: Grassosgarage
99 Ram 5.2 Magnum rough idle - 08/12/15 05:05 AM
I picked up a '99 4x4 with a 5.2. It had been sitting a long time but fired up running rough. Replaced plugs, wires, cap, rotor, and had injectors cleaned. Truck runs much better but still a rough idle feels like a dead miss but runs well at higher rpm. Suggestions for troubleshooting ?
Posted By: HotRodDave
Re: 99 Ram 5.2 Magnum rough idle - 08/12/15 05:11 AM
If you have access to a scanner watch for misfire.
Check for miss the old way, unplug plug wires one at a time.
Compression test
Posted By: mopars4ever
Re: 99 Ram 5.2 Magnum rough idle - 08/12/15 02:16 PM
possible intake plenum gasket leak, look in intake for signs of oil
Posted By: Grassosgarage
Re: 99 Ram 5.2 Magnum rough idle - 08/12/15 04:48 PM
I've read about the plenum leak but don't understand that causing a dead miss. What about the idle air control?
Posted By: John_Kunkel
Re: 99 Ram 5.2 Magnum rough idle - 08/12/15 07:00 PM
Try some throttle body cleaner.
Posted By: bobby66
Re: 99 Ram 5.2 Magnum rough idle - 08/13/15 05:03 AM
Bad gas? Battery low? Maybe pull the iac motor and clean everything up in there.
Posted By: Fat_Mike
Re: 99 Ram 5.2 Magnum rough idle - 08/13/15 04:45 PM
Can you smell gas under the hood? Bad injector seals will cause that symptom...