* Fuel Pump: This is the most common suspect. The pump might be weak, failing to build sufficient pressure to push fuel to the injectors. It could be failing intermittently, working when the engine is already running (due to heat or residual pressure) but struggling to prime when cold.
* Fuel Pump Relay: The relay acts as a switch for the pump. A failing relay might not be sending power consistently to the pump, leading to the starting issues.
* Fuel Filter: A clogged fuel filter restricts fuel flow. While this is a common issue, it usually causes poor running *even when* the engine is running, rather than just preventing starting. However, a severely clogged filter *could* cause this.
* Crankshaft Position Sensor (CKP): While not directly fuel-related, the CKP sensor tells the engine's computer when to inject fuel. A failing sensor could cause the computer to delay or miss the fuel injection timing, especially during startup.
* Fuel Injectors: Though less likely to be the *sole* cause, sticking or faulty injectors could prevent fuel from being sprayed into the cylinders even if there's pressure. This would usually manifest as rough running or misfires even while the engine is running. However, a combination of a weak pump and slightly clogged injectors could exhibit this symptom.
* Ignition System (less likely): While the need for starting fluid strongly suggests a fuel problem, issues with the ignition system (distributor cap, rotor, ignition coil, wires) could also contribute. However, these would typically lead to poor running even after starting.
Troubleshooting Steps:
1. Check fuel pressure: This is the most important step. You need a fuel pressure gauge to measure the pressure at the fuel rail. Compare the reading to the manufacturer's specification (found in a repair manual). Low pressure confirms a fuel delivery problem.
2. Inspect fuel pump relay: Visually inspect the relay for damage. You can also try swapping it with a known good relay (of the same type) as a simple test.
3. Inspect the fuel filter: Check for visual signs of clogging (dirt, debris).
4. Listen for the fuel pump: When you turn the ignition key to the "on" position (but before cranking), you should hear a brief humming sound from the fuel pump (often located near the fuel tank). If you don't hear it, the pump or relay is likely the problem.
5. Check the CKP sensor: This requires more advanced diagnostics, often needing a scan tool to check for error codes.
Important Note: Continuing to start the van with starting fluid is extremely dangerous. It's a highly flammable substance and could lead to a fire. Diagnose and fix the underlying problem as soon as possible. Avoid driving the van until the issue is resolved.
