* Timing: The most likely culprit. Even with spark, if the timing is significantly off, the engine won't fire properly. This needs to be checked with a timing light. A jumped or slipped timing belt is a possibility.
* Compression: Low compression in one or more cylinders will prevent starting, even with spark and fuel. A compression test is essential to rule this out. Worn piston rings, valve problems, or a blown head gasket can cause low compression.
* Crankshaft Position Sensor (CKP): This sensor tells the ECU the position of the crankshaft, crucial for precise spark timing. A faulty CKP sensor can result in no start.
* Cam Position Sensor (CMP): Similar to the CKP, but for the camshaft. A faulty CMP sensor will also lead to timing issues and prevent starting.
* Fuel pressure: While you say there's fuel, ensure the fuel pressure is adequate. A weak fuel pump or clogged fuel filter might deliver insufficient pressure. A fuel pressure gauge is needed to check this.
* ECU Issues: Though less likely if you have spark, a problem with the Engine Control Unit (ECU) could prevent it from correctly sequencing the fuel and spark. This is harder to diagnose and might require professional help.
* Distributor Issues (if applicable): If your Talon has a distributor, check the rotor, cap, and wires for wear or damage. While unlikely with spark, a weak component can hinder starting.
Troubleshooting Steps:
1. Check the timing belt: Visually inspect for damage or slippage. A timing light is crucial to verify timing accuracy. Incorrect timing is a very common cause of this problem.
2. Perform a compression test: This is a critical step to assess engine health.
3. Check fuel pressure: Use a fuel pressure gauge to verify that the fuel pressure is within the manufacturer's specifications.
4. Inspect the CKP and CMP sensors: Check for damage, corrosion, or loose connections. If possible, try replacing them or testing their output with a multimeter (consult a wiring diagram).
5. Examine the distributor (if equipped): Look for wear, damage, or cracks on the distributor cap and rotor. Replace if necessary.
6. Check all fuses and relays: Ensure all fuses and relays related to the ignition system are functioning correctly.
If you're not comfortable performing these checks yourself, it's best to take your Talon to a qualified mechanic. They have the tools and expertise to diagnose the problem accurately. Remember to specify that you have spark and fuel. This significantly narrows down the possibilities.
