If the idling speed is too high, it would cause this problem.
After cleaning the throttle body, the idle would increase and you need to reduce it by adjusting the idle adjust screw. It is the brass (copper) screw on top inner part of throttle body. Turning it clockwise would reduce the idling speed.
Idling speed when engine is warmed up should be 700 rpm. The IAC and cold start control valve are 2 other things you need to check.
Remove the air cleaner hose and start engine.
Just inside the throttle body are 2 ports for air flow, one to the cold start/IAC and the other for the idle control.
After engine is warmed up, use a finger to close one port and if engine speed drops drastically, that is the area where you need to check the problem. Close each port individually to test.
Monday, October 30th, 2017 AT 7:33 PM