Symptom: Engine cranks but won’t start when hot; starts fine when cold. Cause: Fuel evaporation (vapor lock) in fuel rail or failing coolant temperature sensor. Fix: Test coolant temp sensor resistance (spec: 2-3k ohms at 20°C, 200-400 ohms at 80°C). Replace if faulty. Ensure fuel pressure regulator is holding residual pressure.
The water pump is driven by the timing belt. Never skip replacing the water pump when you do the timing belt. The pump costs $50. A blown pump leaks coolant onto the belt, causing it to snap.
Bleeding procedure (critical): The 1G-FE has a high point air trap on the thermostat housing.
If you hear a clattering sound on cold start or at idle, your HLAs are collapsed. Do not replace them immediately. Follow the manual’s “bleeding procedure”:
If ticking persists, you need to remove the camshafts and compress each HLA in a vice to check for “sponginess.” Replace any that compress more than 1mm.
