Fuel System Issues (Beyond what you've already checked):
* Fuel Injectors: While you replaced the *distributor cap* and *ignition module*, the *fuel injectors* themselves could be faulty. They might be sticking open, constantly delivering fuel even when the engine isn't cranking. A simple visual inspection might reveal leaks, but a proper test with a fuel pressure gauge would be needed.
* Throttle Body Injection (TBI) Unit: The TBI unit itself could be malfunctioning. Internal components could be failing, leading to excessive fuel delivery. A professional rebuild or replacement might be necessary.
* Fuel Pressure Regulator (FPR) (Double-check): Although you replaced it, ensure the new regulator is functioning correctly and is properly installed. A faulty regulator could maintain excessive pressure in the fuel rail, leading to flooding. Double-check the vacuum line connection to the regulator.
* Return Line: Verify there's no blockage or kink in the fuel return line. A clogged return line prevents excess fuel from returning to the tank.
* Fuel Pump Wiring: Although you replaced the pump, ensure the wiring to the pump and other fuel system components is correct and undamaged. A short circuit could keep the pump running constantly.
Ignition System Issues (Beyond what you've already checked):
* Crankshaft Position Sensor (CKP Sensor): A faulty CKP sensor will prevent the engine from getting a proper spark signal, but a severely faulty one might keep the engine from starting at all.
* Ignition Control Module (ECM): You replaced the *ignition module*, but the *engine control module (ECM)* controls the timing and fuel delivery signals to the ignition system and fuel injectors. A malfunctioning ECM could be the culprit. This requires more advanced diagnostics.
Other Possibilities:
* Vacuum Leaks: Large vacuum leaks can disrupt fuel delivery and the air/fuel mixture, causing flooding or preventing the engine from starting. Carefully inspect all vacuum lines and connections.
* Intake Manifold Gasket: A leak in the intake manifold gasket can introduce unmetered air, disrupting the fuel/air mixture and causing problems.
* Computer/ECM Issues (Again): While you replaced some components, the engine control module (ECM) could be sending incorrect signals to the injectors, causing the flooding. This often requires a professional diagnostic scan tool.
Troubleshooting Steps:
1. Fuel Pressure Test: This is CRITICAL. Use a fuel pressure gauge to check the pressure in the fuel rail while cranking the engine. It should be within the specifications listed in your repair manual.
2. Visual Inspection: Carefully inspect all fuel lines, connectors, and vacuum lines for leaks, cracks, or loose connections.
3. Check for Codes: If possible, connect a code reader to retrieve any diagnostic trouble codes (DTCs) stored in the ECM. These codes can provide valuable clues about the problem.
4. Professional Diagnosis: If you've exhausted all the above steps, it's time to seek professional help. A qualified mechanic with a scan tool can properly diagnose the problem.
Remember safety first! Work in a well-ventilated area and disconnect the battery's negative terminal before working on the fuel system. Fuel is highly flammable.
