I just went for a drive and noticed the truck idling erratically. It was staying around 500rpm, but the needle would bounce up and down between 400 and 600. I disconnected my battery today to clean off the terminals. Does it have to relearn the idle? It wasn't doing this yesterday. Thanks for any help.

 

It may just be the computer relearning if you had it unplugged long enough to reset it. Give it a few hours of driving and see if it still does it.

 

I had it unplugged for maybe 30 minutes. I took it for another drive, even a run through the Taco Bell drive through, it was fine until I got home. I let it sit and run for a minute to watch it, it started doing it again.

 

it is your throttle positioning sensor, it is bad, 106.00 for a replacement, simple to replace. 2 small screws hold it onto the throttle body with an electrical conection, if you still have the factory air hat on, you will have to remove it to get at the sensor

 

Have you filled up the gas tank lately? If your spark plugs are old, try changing them out/tune up.

 

I fill it up almost everyday. I drive around 100 miles a day, so I have to. It wasn't doing it until I disconnected the battery. I had a car somewhere along the way that, if you disconnected the battery, you had to let it run for 10 minutes to relearn the idle. I thought maybe that was why.

 

It could be bad gas, I would fill the tank and see if it goes away. I got some bad gas about a 8 months ago or so and it sounded horrible.

 

I drove it around again today, didn't notice the problem at all. I filled it up with high octane gas, and put in some fuel injector cleaner. I'll drive it for a few days and see what happens.

 

Carquest has them for around $50.

 

Mine would do this to the point of stalling and it was because of the EGR Valve. It was about 50 bucks and two PITA bolts.