Stumbling during initial throttle opening could be due to
1. Sparks misfiring.
2. Fuel injectors operations.
3. Fuel pressure.
4. Valve clearances too tight.
5. TPS out of adjustment
Since vehicle had not been started for quite some time, let it have some running time to see if the problem evens out.
Starting only with WOT can mean a fault with the TPS or its adjustment.
Check to see if there are ant trouble codes.
Friday, January 6th, 2012 AT 10:26 AM