Fuel Delivery Problems:
* Empty Fuel Tank: The most obvious, but worth checking first!
* Fuel Pump Failure: The fuel pump might be failing to deliver fuel to the engine. This could be due to a faulty pump itself, a blown fuse, a bad relay, or a problem within the pump wiring. Listen carefully near the fuel tank – you should hear a humming sound when the ignition is turned on (for a few seconds). If you don't hear it, this is a strong suspect.
* Clogged Fuel Filter: A blocked fuel filter restricts fuel flow. This is a relatively inexpensive and easy part to replace.
* Fuel Pressure Regulator Issues: A malfunctioning fuel pressure regulator could be letting fuel pressure drop too low, leading to insufficient fuel delivery.
* Clogged Fuel Injectors: Clogged injectors can prevent proper fuel spray into the combustion chambers. This often requires professional cleaning or replacement.
* Fuel Lines: A kinked, cracked, or blocked fuel line can interrupt fuel flow. Inspect the fuel lines visually for any damage.
Other Potential Issues (less likely but possible):
* Ignition System Problems: While you say it's turning over, weak spark could still contribute to a no-start condition even if it cranks. Check your spark plugs and ignition coil.
* Airflow Sensor: A faulty air flow sensor could cause the fuel system to deliver an incorrect fuel/air mixture.
* Computer (ECU) Issues: Though rare, a faulty engine control unit (ECU) could be preventing proper fuel delivery. This is usually diagnosed last.
Troubleshooting Steps:
1. Check the fuel level: This is the absolute first step.
2. Listen for the fuel pump: Turn the ignition key to the "on" position (don't crank the engine). Listen carefully for the fuel pump's humming sound near the fuel tank.
3. Check the fuel filter: Locate the fuel filter and visually inspect it for damage. If it's easily accessible, consider replacing it.
4. Check the fuel pressure: This requires a fuel pressure gauge and is best done by a mechanic or someone experienced with fuel systems. Low fuel pressure confirms a problem in the fuel delivery system.
5. Inspect fuel lines: Look for any visible cracks, kinks, or damage to the fuel lines.
6. Check the spark plugs: Inspect the spark plugs for wear, fouling, or damage. Testing them for spark is recommended.
If you're not comfortable working on fuel systems, take your RX-7 to a qualified mechanic. Fuel systems can be dangerous if not handled properly. They will have the tools and expertise to diagnose the problem accurately and safely. Mentioning the symptoms ("cranks but sounds fuel-starved") will help them focus their diagnostic efforts.
