my Cadillac Escalade won't start after filling up gas what could be wrong

Symptoms

• Check engine light illuminated
• Engine cranks but does not start
• Fuel smell in the engine compartment
• Fuel gauge may indicate full despite recent filling
• Possible stalling shortly after starting

Diagnostic Steps

1. Scan for error codes using an OBD-II scanner to check for any fault codes related to the fuel system or engine.
2. Inspect the fuel pump operation by listening for the pump priming when the ignition is turned on.
3. Check the fuel pressure at the rail using a fuel pressure gauge to ensure it meets specifications.
4. Examine the fuel filler neck and cap for any signs of damage or improper sealing.
5. Inspect the EVAP system for leaks or blockages that could cause fuel vapor lock.
6. Verify the integrity of the fuel injectors and their electrical connections.

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface, and the engine is cool.
• Disconnect the battery to prevent any electrical shorts.

2. Fuel Pump Inspection

• Tools Required: Fuel pressure gauge, multimeter
• Remove the fuel pump relay from the fuse box.
• Use a multimeter to check for voltage at the fuel pump connector while cranking the engine.
• If no voltage is present, trace the wiring back to the fuel pump relay and ECM for potential issues.

3. Fuel Pressure Check

• Tools Required: Fuel pressure gauge
• Attach the fuel pressure gauge to the fuel rail service port.
• Turn the ignition to the "ON" position without starting the engine and read the pressure. It should be within manufacturer specifications (typically around 55-62 psi).
• If the pressure is low, consider replacing the fuel pump.

4. Inspect EVAP System

• Visually inspect for any damaged hoses or connections in the EVAP system.
• Use a smoke machine to test for leaks in the system, focusing on the charcoal canister and associated lines.
• Replace any faulty components as needed.

5. Fuel Injector Check

• Tools Required: Multimeter, injector cleaning kit (if needed)
• Disconnect the electrical connectors from each fuel injector.
• Use a multimeter to check the resistance of each injector; it should typically be around 12-16 ohms.
• If any injectors are faulty, replace them.

6. Reassemble and Test

• Reconnect the battery.
• Reinstall any removed components and relays.
• Start the vehicle to ensure proper operation.