Service Tips J20A Engine

How to check thermostat

It was very simple in accordance the function of thermostat itself, so to determine the condition of thermostat :

1. Immerse thermostat in water and heat water gradually.

      2. Check that valve starts to open at specific temperature.

• Temperature at which valve begins to open 80 - 84 celcius
• Temperature at which valve become fully open 95 - 97 celcius.
• Valve lift more than 8 mm at 95 celcius.

If thermostat starts to open at a temperature substantially below or above specific temperature, thermostat unit should be replaced with a new one. If reused, will bring about overcooling or overheating tendency.

Measure fuel pressure

1. Turn ON ignition switch to operate fuel pump for 2 minutes. Repeat this 3 or 4 times, then measure fuel pressure. Its specification is 360 - 400 kPa.
2. Start engine until it reaches working temperature. Measure the fuel pressure. Its specification is 360 - 400 kPa.
3. Stop engine and measure fuel pressure at one minute after engine shut off. Its specification is over 250 kPa.