I drive a 2004 F 150, here is what happened hopefully you guys can help.

I start the truck and start to drive, I get to a stop sign and put on the brake but the truck keeps trying to move forward. I notice the rpm needle jumping from .5 to the 1 ( I believe its in thousands), a few minutes later I get to a red light and a again it tries to move forward I have to press hard on the brake to keep it from moving, at that time I notice that temp. needle has not moved. After a couple minutes the temp needle starts to move slowly, once the engine warmed up the truck worked fine. It took about 12 minutes for it to warm up.

Does any one know why the engine is taking so long to warm up or why the rpm is jumping like that. A friend suggested it might be the o2 sensor.

I don't really know that much about the o2 sensor just that ( correct me if I'm wrong) it controls the amount of air that gets mixed with fuel, and that it activates when the engine is warmed up. Again any help would be appreciated.

 

I know this sounds stupid, but its been discussed lately around here, make sure your foot isnt grabbing the side of the gas pedal while your pushing the brake pedal. I did this when i test drove my 2004 and thought i was going to hit the car in front of me that was stopped. i dont know if temp being slow would have anything to do with pushing the brake and gas at the same time, if that is what is going on, but look into that next time. You might be doing it and not even know it. I know i did!

 

I see how that could be possible, but that's not what is going on here. It stops jumping once the engine is warmed up.