1. Fuel System:
* Empty Tank: Sounds obvious, but check the fuel gauge. A faulty gauge is possible, so verify.
* Fuel Pump: The pump might be failing, delivering insufficient fuel, or completely dead. You might hear a faint whine when you turn the key to the "on" position (before cranking) – that's the pump priming. Absence of this whine suggests a problem.
* Clogged Fuel Filter: A clogged filter restricts fuel flow, preventing the engine from getting enough.
* Fuel Pressure Regulator: A faulty regulator can lead to low fuel pressure.
* Bad Fuel Injectors: Injectors might be clogged, leaking, or electrically malfunctioning, preventing fuel delivery to the cylinders.
2. Ignition System:
* Ignition Coil: This component provides the high voltage needed for sparking. A failing coil can cause misfires or no spark at all.
* Spark Plugs and Wires: Worn, damaged, or fouled spark plugs prevent proper ignition. Inspect the plugs for damage, carbon buildup, or gaps that are too wide or narrow. Similarly, cracked or damaged ignition wires can prevent spark delivery.
* Distributor (if applicable): Older vehicles may have distributors. A problem with the distributor cap, rotor, or pickup coil can prevent spark. The Bravada likely uses a coil-on-plug system, so this is less likely.
* Crankshaft Position Sensor (CKP): This sensor tells the engine control module (ECM) the position of the crankshaft, enabling proper timing of the spark. A faulty sensor prevents the engine from starting.
* Camshaft Position Sensor (CMP): Similar to the CKP, but for the camshaft. A faulty CMP can also prevent starting.
3. Engine Related Issues:
* Security System: The vehicle's anti-theft system might be preventing the engine from starting. Try a spare key if applicable.
* Battery: While the engine is cranking, a weak battery might not provide enough power for the starter *and* the ignition system. Check the battery voltage.
* Starter: Although it's turning over, a weak starter might not be cranking fast enough.
* Timing Belt/Chain: A broken timing belt/chain (very serious!) results in no combustion. This is less likely if the engine is cranking normally, but should be considered if there was any recent engine work.
Troubleshooting Steps:
1. Check the obvious: Fuel level, battery voltage, and spare key.
2. Listen carefully: Listen for the fuel pump whine when you turn the key to the "on" position.
3. Visual inspection: Check spark plugs and wires for visible damage.
4. OBD-II Scanner: Use a scanner to read any diagnostic trouble codes (DTCs) stored in the ECM. This can point to the specific problem area. Auto parts stores often offer free code reading.
5. Professional help: If you're not comfortable working on your vehicle, take it to a qualified mechanic.
Don't attempt repairs beyond your skill level. Working on the fuel system involves working with flammable materials and should be approached carefully. Incorrect procedures can cause further damage or even injury.
