when i start my car to warm up after one or two minute it start to rev up like some one is pressing and releasing the gas peadle ? my second question, when i am driving at 60mph i notice my rpm is at 3000 what could be the problem.
my car rev up by it self some one help me on 1994 Acura Legend
More specifically, the problem is the cold idle valve that is controlled by the coolant. As the car warms up and goes in to closed loop ( where the computer is now controlling the fuel system ), the car will idle up to about 1800 rpm and then the computer will cut the injectors and bring down the idle speed which causes a surge that sounds like someone is pressing and releasing the gas pedal. So, replace the Coolant Controlled Idle valve. ( many Honda/Acura vehicles have 2 i.e an Electronic Idle Valve and a Coolant Controlled Idle valve that is used during cold start and warm up ) If the vehicle has just one valve then it will be integrated in to 1 unit.
idle air control valve, get a scantool and see if you have any codes