hi, i have a 1998 e 150 with a 4.2l v6, as i go to start it up when the motor is cold only, it idles really rough for 30 secs. or so, then clears up and runs perfect, where do i start, since it runs so good all the other time..thanks

 

Maybe a bad engine temp sensor that tells the computer when the engine is cold so it can richen the fuel mixture. Just like a choke did on older cars.

 

Are you showing the Check Engine Light? If so have you yet pulled the codes?

I'd strongly suspect the Idle Air Control valve is hanging up just a bit. Before you start changing things though get any codes---with this condition there should be something that triggered the monitoring sensors.

 

I got a set of lifetime free replace plug wires! Fixed the problem. I need to replace the wires about every 25000-30000 miles. Not sure why except plug wires are all made in China today.