Every time I start my 4.7 V-8 engine, warm or cold, it immediately jumps up to 1,500 rpms then settles down to 600 rpm. I have replaced the throttle position sensor but problem remains.
Tuesday, December 11th, 2012 AT 6:00 PM
It's doing exactly what it's supposed to do. That's called the "idle flare-up". All fuel injected engines do that. It's when it doesn't do it that we read about the complaints of hard starting and stalling at stop signs. The TPS has nothing to do with idle speed. It mainly tells the Engine Computer which way and how fast the throttle is being moved to prevent a hesitation or stumble on acceleration.