* Fuel Injectors: Faulty fuel injectors can spray too much fuel, leading to flooding. One or more injectors might be stuck open or delivering excessive fuel. This is a very likely culprit given the other parts have been checked. A fuel pressure test is crucial here to rule out excessive pressure.
* Intake Air Leak: A large vacuum leak can cause a rich fuel mixture (too much fuel, not enough air). This can lead to flooding and the smell of unburnt fuel in the exhaust. Check all intake manifold gaskets and connections for cracks or loose clamps.
* EGR Valve: A malfunctioning Exhaust Gas Recirculation (EGR) valve can introduce excessive exhaust gases into the intake, disrupting the air/fuel mixture and causing a rich condition. A sticking or faulty EGR valve is less likely to cause *flooding* specifically, but could contribute to the rich mixture and popping.
* Distributor (if applicable): While you mentioned the coil, a 1995 Windstar might have a distributor. Worn distributor components (rotor, cap) could cause misfires and poor ignition, leading to unburnt fuel and a smell of gas.
* Computer/ECU Problem: Though less likely given your other checks, a problem with the Powertrain Control Module (PCM) or Engine Control Unit (ECU) could be causing incorrect fuel delivery or ignition timing. This would require a diagnostic scan tool to detect.
* Catalytic Converter: A clogged catalytic converter can cause backpressure, leading to incomplete combustion and the smell of gas. However, this is less likely to cause the *flooding* itself.
Troubleshooting Steps:
1. Fuel Pressure Test: This is the most critical step. A mechanic can perform this test to measure fuel pressure at the rail. Excessive pressure strongly indicates a faulty fuel pressure regulator (despite replacing it, it's possible a faulty replacement was installed or another component affecting fuel pressure is at play). Low pressure points to a fuel pump issue.
2. Vacuum Leak Test: Use a vacuum gauge or smoke machine to check for leaks in the intake system.
3. Inspect Fuel Injectors: Visually inspect the injectors for leaks or signs of damage. A fuel injector cleaner might temporarily help, but likely won't solve a completely faulty injector.
4. Check EGR Valve: Inspect the EGR valve for sticking or carbon buildup.
5. Scan for Diagnostic Trouble Codes (DTCs): Use an OBD-II scanner to check for any stored trouble codes in the PCM. This could pinpoint the problem area.
Without a diagnostic scan and fuel pressure test, it's difficult to pinpoint the exact cause. A qualified mechanic is best equipped to diagnose this complex issue effectively. Trying to fix it piecemeal might lead to further damage or wasted time/money.
