4.6L Rough Idle
o.k. guys, i need some input. i have a '97 f150 SC 4x4. My truck is idling rough, but it only does it maybe once a day. When i come to a stop, and the truck is hot, the rpm's start dropping to 500 or less, and the truck starts to act like it wants to die. its actually never died. if i give it some gas, it will start sputtering, and finally take off. it also tends to do this more when i'm towing a load. the truck has 105k on it. Here's what i've done so far:
1. New plugs and plug wires
2. new fuel filter (its in the correct direction)
3. new pcv valve
4. new IAC valve
The biggest problem is that i can't get the truck to repeat the problem in the drive way. i would love to be able to pull the spark plug boots to check for a misfire. It set a light about 6 months ago, but it went out shortly after that. will the code still be saved? the light has not came back on. any ideas? i hate to keep putting money in parts that don't need to be changed. i'm thinking: DFPE, EGR, Coil Packs, MAF, and maybe the Fuel Pump. any ideas would be greatly appreciated.