Checking the vacuum in the intake manifold (Mitsubishi Space Star)

Measuring vacuum is a reliable and relatively cheap way to diagnose an engine. The vacuum gauge readings can provide information about the condition of the cylinder-piston group, the tightness of the cylinder head gasket, intake and exhaust manifolds, the correctness of the fuel and exhaust system adjustments, the exhaust gas throughput, the condition of the valves (whether they are stuck or burnt out) and valve springs, and also check the correctness of the ignition timing and valve timing adjustments during engine operation.

1. Start the engine and warm it up to a temperature of 80-95°C.

2. Connect the tachometer.

3. Install a tee into the vacuum hose connecting the fuel pressure regulator and the air intake chamber, then connect a vacuum gauge to the tee.

4. Start the engine and let it idle. Make sure that the crankshaft speed is correct and read the pressure gauge (Fig. 3.12).

Minimum value on the vacuum gauge: 60 kPa