Use of cylinder pressure gauge

Cylinder pressure gauge is a kind of measuring tool specially used to check the gas pressure in the cylinder.

Start the engine, run it to normal working temperature, and unscrew the spark plug (gasoline engine) or fuel injector (diesel engine) of the cylinder to be tested.

The gasoline engine must fully open the throttle valve and choke valve and press the conical rubber ring of the cylinder pressure gauge on the spark plug seat hole. The diesel engine must use the threaded interface cylinder pressure gauge, and screw the threaded interface of the cylinder pressure gauge into the injector seat hole.

Use the starter to drive the crankshaft to rotate for 3 ~ 5s, and keep the engine speed at 150 ~ 180 rpm (gasoline engine) or 500 rpm (diesel engine). At this point, the pressure indicated by the cylinder pressure gauge is the cylinder compression pressure.

Press the bleeder valve on the cylinder pressure gauge, and the pointer will return to zero.

In practice, each cylinder should be repeated 2-3 times.

There are two types of joints. One is a threaded joint, which can be screwed on the spark plug or in the rib hole of the fuel injector; The other is a conical or stepped rubber joint, which can be pressed on the hole of a spark plug or an injector, and the joint is communicated with a pressure gauge through a conduit.

There are also two kinds of catheters: one is soft catheter and the other is hard metal catheter. The hose is used to connect the threaded pipe joint and the pressure gauge. Hard conduit is used to connect rubber joint and meter head.

Use of cylinder pressure gauge

(1) Start the engine. Stop when the engine water temperature rises to about 80C.

(2) Blow off the dust outside the spark plug with compressed air, remove the spark plugs of each cylinder, and open the throttle valve and choke valve.

(3) Remove the exhaust gas in the cylinder, put the rubber head of the cylinder pressure gauge on the spark plug hole of the first cylinder and press it hard.

(4) Turn the crankshaft quickly with a starter or crank at a speed of about 180 rpm. Write down the reading of the pressure gauge and record 2-3 tests. Then measure the remaining cylinders in turn.

(5) The cylinder pressure is lower than the standard (Jiefang CA 14 1, Dongfeng EQ 140). 0.833Mpa), add 20-30g new lubricating oil to the top of the piston, and conduct pressure test again. If the rise is obvious, it means that the piston ring is worn. If the pressure is constant, it means that the valve or cylinder gasket is leaking.

Attached:

Inspection of cylinder pressure gauge

(1) Appearance damage.

(2) whether the sealing surface is in good condition.

(3) Check the reading of the pointer.

Functions of cylinder pressure gauge:

Check whether the pressure in the engine cylinder meets the standard value.

The parameters of cylinder pressure gauge of gasoline engine are 0 ~ 980 kPa.

The parameter of cylinder pressure gauge of diesel engine is 0 ~ 1960 kPa.