* Fuel Pump: This is the most common cause. The pump might be failing, clogged, or not getting power. Check the pump's power supply (fuse, relay, wiring) and ensure the pump itself is working. You might hear it hum when you turn the key to the "on" position (before cranking). A fuel pressure gauge is essential to confirm pump output pressure.
* Fuel Filter: A clogged fuel filter will restrict or completely stop fuel flow. This is a cheap and easy component to replace, and should be done routinely as part of preventative maintenance.
* Fuel Pump Relay: Even if the pump is good, a faulty relay won't send it power. Swapping the relay with a known good one from a different circuit (if possible) is a quick test.
* Clogged Fuel Lines: There might be debris or blockage in the fuel lines themselves, preventing fuel from reaching the pump or traveling onward. Inspect the lines visually for kinks, cracks, or obstructions.
* Fuel Tank: There might be a problem within the fuel tank itself, such as debris or a faulty sending unit. This is less likely, but possible.
* Wiring Issues: Check all wiring related to the fuel system, including the power and ground wires for the pump and any sensors related to fuel delivery. Look for broken, corroded, or loose connections. A short circuit could even be blowing a fuse.
* Fuel Pressure Regulator Installation: While you replaced it, ensure it's correctly installed and seated properly. A slight misalignment could affect performance.
Troubleshooting Steps:
1. Check the fuel pump relay and fuse.
2. Listen for the fuel pump to prime when the key is turned on.
3. Visually inspect the fuel lines for any obvious problems.
4. Replace the fuel filter.
5. Use a fuel pressure gauge to measure the fuel pressure at the fuel rail. This will definitively tell you if the pump is working and providing adequate pressure. Without a gauge, you're essentially guessing.
6. If pressure is low or absent, suspect the fuel pump.
If you're not comfortable working on your fuel system, it's best to take your Cheyenne to a qualified mechanic. Working with fuel systems can be dangerous if not handled properly. The fuel pressure gauge is particularly critical for accurate diagnosis.
