Hard Start
- Check fuel pressure. If pressure bleeds off immediately, check for fuel lines or injector leaks with ignition on and engine stopped. Cap fuel return line at throttle body.
- Turn ignition on, then off while noting pressure drop. If pressure drops rapidly, check for faulty fuel pump check valve or fuel leaks in the tank. If pressure holds with ignition on and return line capped, inspect fuel pressure regulator for leakage.
- Check ignition timing. Check HEI voltage output, ignition system components and spark plug condition. Check spark plug wire resistance. Replace spark plug wire if resistance exceeds 50,000 ohms.
- Check for sticking or binding TPS or throttle linkage. Check for leaking intake manifold or throttle body gaskets. Check for restricted exhaust system.
- Check for restrictions at MAP sensor vacuum ports. Check for vacuum trapped in MAP sensor. Check coolant sensor and MAT sensor accuracy. Check for damaged engine components.