Hi,
I have a 2002 Sienna. It runs great until recently. When the engine is cold, I need to pump the gas pedal and turn the key to start the engine. After the engine is ignited, I release both the key from START position and the gas pedal, then the idle drops to zero quickly and the engine stops.
The only way to start the engine is to turn the key to START, crank the engine, press on the gas pedal to maintain the idle speed (above 1000 rpm) to keep the engine running, release the key, until the temperature climbs up. At this point the idle speed is back to normal (about 750 rpm in neutral after releasing the gas pedal) and the engine won't stop.
What is causing this problem and how can it be fixed.
Thanks.
Joe