Possible Sources of the Leak:
* Fuel Supply Line: This is the most probable cause. The fuel supply line carries fuel from the fuel filter/pump to the injector pump or common rail. A crack, loose connection, or failing O-ring in this line near the throttle linkage would cause a leak in that area.
* Injector Return Line: Less likely given the description. While the return line carries fuel *back* from the injector, a leak here would be unusual to drip down onto the throttle mechanism. However, a damaged return line could be a possibility.
* Injector Pump (or Common Rail, if applicable): A leak from the pump or rail itself is possible, but less likely to drip directly onto the throttle. This would typically result in a more substantial leak. (This depends on whether it's a VP44 type injection pump or a common rail system - which type depends on the exact year/model of your engine).
* Fuel Filter Housing: A leak in the filter housing (especially if it has a faulty O-ring or seal) is a possibility, but again, the location makes this less likely.
How to Fix It:
1. Safety First: Diesel fuel is flammable. Before attempting any repairs:
* Turn off the engine completely.
* Disconnect the negative battery terminal.
* Ensure adequate ventilation. Diesel fumes are harmful.
* Wear safety glasses and gloves.
2. Locate the Leak Precisely: Carefully inspect the entire fuel system in the vicinity of the throttle lever. Look for wetness, fuel stains, or the source of the dripping. A flashlight and possibly a mirror might help.
3. Identify the Leaking Component: Once you've pinpointed the leak, determine the specific component (fuel line, O-ring, etc.).
4. Repair or Replacement: This depends on what you've found:
* Loose connection: Tighten clamps or connections securely.
* Cracked fuel line: Repair with a fuel line repair kit (if appropriate) or replace the damaged section of the line. This will likely require specialized fuel line clamps or connectors.
* Failing O-ring: Replace the O-ring.
* Damaged injector pump or common rail: This requires professional help and is a much more involved repair.
5. Testing: After the repair, run the engine and monitor the area carefully for further leaks.
Important Note: This is a complex repair. If you are not experienced in working on diesel fuel systems, it is strongly recommended to seek help from a qualified mechanic. Working on the fuel system improperly could lead to serious injury or damage to your vehicle. Incorrectly tightening fuel lines could lead to further leaks or potentially fire. If you're unsure, get professional assistance.
