* Fuel Pump: This is the most likely culprit. The brief running suggests the fuel pump is *weak* or intermittently failing. It can pump enough fuel to briefly run when you add extra fuel directly into the throttle body, bypassing the pump, but it can't keep up with demand under normal operation.
* Fuel Filter: A clogged fuel filter will restrict fuel flow, leading to similar symptoms. The extra fuel temporarily overcomes the restriction.
* Fuel Pressure Regulator: This component regulates the fuel pressure in the system. A faulty regulator could be failing to maintain the correct pressure, leading to insufficient fuel reaching the injectors.
* Injectors: While less likely given the brief running, clogged or failing fuel injectors could prevent adequate fuel delivery. However, if only one injector was failing, the engine likely wouldn't run at all, even temporarily.
* Ignition System (less likely): While the brief running on added fuel points away from this, a weak spark, failing coil, or distributor issues *could* contribute to a problem if the fuel supply was already marginal.
What to do:
1. Do NOT continue pouring gas into the throttle body. This is incredibly dangerous and could lead to a fire.
2. Check the fuel pump: This is the best place to start. Listen carefully for the fuel pump whirring when you turn the ignition key to the "on" position (before cranking). A faint or absent whirring sound is a strong indicator of a failing pump. You may need a helper to listen while you turn the key.
3. Check the fuel filter: Locate the fuel filter (consult your owner's manual) and inspect it. If it's visibly dirty or damaged, it needs replacing.
4. Check for fuel at the fuel rail: If you have the tools and experience, you might check the fuel rail (where the injectors are) to see if fuel pressure is present when the key is turned to "on." This requires a fuel pressure gauge and caution to avoid injury.
5. Professional help: If you're not comfortable performing these checks, it's best to take your Jeep to a qualified mechanic. They have the tools and expertise to diagnose and fix the problem safely and efficiently.
The fact that the engine ran briefly after adding fuel directly into the throttle body is a significant clue pointing to a fuel delivery problem. Don't ignore this, as continuing to attempt this "fix" is extremely hazardous.
