* Crankshaft Position Sensor (CKP Sensor): This sensor tells the engine's computer the position of the crankshaft. A failing CKP sensor can cause erratic starting, and often leads to a no-start condition. The "pumping the gas" might be giving the engine just enough extra fuel to overcome the sensor's faulty readings. The engine light is likely illuminated due to the misfires resulting from the erroneous signals.
* Cam Position Sensor (CMP Sensor): Similar to the CKP sensor, a faulty CMP sensor misinforms the engine computer about the camshaft's position. This leads to ignition timing problems that can manifest as hard starting and engine light illumination.
* Fuel Pump: While less likely given the need to pump the gas, a weak fuel pump could be struggling to deliver enough fuel pressure consistently. Pumping the gas might be adding just the right amount of pressure needed to prime it. A faulty fuel pump would also set a diagnostic trouble code (DTC).
* Fuel Pressure Regulator: Similar to a weak fuel pump, but this regulates the fuel pressure in the system. A faulty regulator could lead to inconsistent fuel pressure.
* Throttle Position Sensor (TPS): A malfunctioning TPS sensor provides inaccurate information to the engine control module (ECM) regarding the throttle position. This can lead to starting issues.
* Mass Airflow Sensor (MAF Sensor): A dirty or failing MAF sensor provides incorrect information about the amount of air entering the engine. This results in poor fuel mixture which could cause difficulty starting.
What you should do:
1. Get the Diagnostic Trouble Codes (DTCs) read: This is crucial. Take your Jeep to an auto parts store (like AutoZone, Advance Auto Parts, etc.) that offers free code reading. They can use an OBD-II scanner to read the codes stored by the engine control unit. This will give you a much better idea of the specific problem.
2. Don't ignore the engine light: Continuing to drive with the engine light on can cause further damage.
3. Consider professional help: Based on the DTCs, a mechanic can diagnose and repair the problem correctly. Trying to fix this yourself without the right knowledge and tools could lead to more costly repairs.
The need to "pump the gas" is a strong indicator of a problem with the fuel system or the sensors that control the fuel injection. Get those codes read and then seek professional advice.
