Ok i got a yj 2.5 auto no check lights on but when i start if its fine but when i go from p to r it cuts off if i give it some gas it will stay on . I can go from n to r and it starts to cut off but stays on , when i am driving and come to a stop it strats to some time not everytime and when i rev it up it will start to cut off also . I am going to change the fuel filter and check the plugs what else ?
Could be a bad throttle position sensor or a dirty throttle body. May also be Idle Air control (IAC) module.
Throttle position sensor
A throttle position sensor (TPS) is a sensor used to monitor the position of the throttle in an internal combustion engine. The sensor is usually located on the butterfly spindle so that it can directly monitor the position of the butterfly throttle valve.
The sensor is usually a potentiometer and therefore provides a variable resistance dependent upon the position of the butterfly valve (and hence throttle position).
The sensor signal is used by the Engine Control Unit (ECU) as an input to its control system. The ignition timing and fuel injection timing (and potentially other parameters) are altered depending upon the position of the throttle, and also depending on the rate of change of that position. For example, in fuel injected engines, in order to avoid stalling, extra fuel may be injected if the throttle is opened rapidly (mimicking the accelerator pump of carburetor systems).