Publicité
Les langues disponibles
Les langues disponibles
INSTRUCTION OF GAS CYLINDER COMPRESSION TESTER
PREPARATION
1. Start engine for 10 minutes approximately or until the motor up to the temperature in
normal operation.
2. Stop engine then disconnect the spark plug and connecting wires. Have the wires
marked with number to distinguish and reconnect correctly.
3. Clear away the dirt around the spark plug and remove it. Put them in order on a clean
surface to compare compression problems according to the condition.
4. Remove the high-tension wires from the center of the distributor and ground them. If
an electronic ignition system, then disconnect the electronic ignition device or remove
the primary battery terminal from the coil. If a GM HEI susterm, then disconnect the
primary wire in the distributor cap.
5. Remove air filter then fit throttle plate Remember, do not damage the connector or the
components on the throttle.
6. Choose an appropriate adapter and attach it to the head of pressure tester (spark plug
hole, see Fig,1). To reach easily the hole and connect to the head of the gauge, a cone
rubber regulator is used to instend of a hose assembly (see Fig.2). But, the reading of
pressure got from this method is not so accurate.
TESTING
1. Connect the quick coupling vs head of air gauge assembly to the pipe of the cone
rubber hose then screw the pipe in or push the rubber hose into the spark plug hole.
2. Start engine to run at least 4 compression strokes or until the pressure of air gauge
remains a fix level. Then, stop engine and write down the reading on air gauge.
3. Remove the tester and return air gauge to zero. Fit the spark plug and the connecting
wires back and continue the test of the next cylinder.
RESULTS ANALYSIS
1. If a normal cylinder, the pressure should be getting higher after each compression
stroke then to the maximum. The pressure of each cylinder in the same engine should
be within the standard set by the manufacturer.
2. If the pressure remain the same or not getting higher until several compression strokes,
then the valve is probably clogged.
3. If the pressure in two adjacent cylinders is not more than 20 lbs, lower than another
cylinder, then the gasket in the head is probably damaged.
4. If the pressure is much higher than the standard set by the manufacturer then probably
carbon residue is existed.
5. If the pressure is low or a big difference between the cylinders, get a teaspoon of
SAE30 oil into each cylinder then test again. After this test, if the pressure increased
much, the problem improbably the cylinder was not seated properly or the piston ring
was worn out. If the pressure not changed much, then the valve is probably leaked.
6. Please refer to the manufacturer's maintenance manual about the standard pressure
in the cylinder.
V GB
4/6
Publicité
