Perform the following steps in order to conduct a compression
test:
- Conduct the following steps in order to check cylinder compression:
1.1. | Engine should be at room temperature. |
1.2. | Disconnect the BAT terminal and the terminal connector from the
distributor. |
1.3. | Remove the spark plugs. |
1.4. | Block the throttle body plate wide open. |
1.5. | Battery should be at or near full charge. |
- For each cylinder, crank engine through four compression strokes.
- The lowest reading cylinder should not be less than 70% of the
highest.
- No cylinder reading should be less that 689 kPa (100 psi).
Important: The results of a compression test will fall into the following categories:
- Normal -- Compression builds up quickly and evenly to specified
compression on each cylinder.
- Piston Rings -- Compression low on first stroke. Tends to
build up on following strokes but does not reach normal. Improves considerably
with addition of oil.
- Valves -- Compression low on first stroke. Does not tend
to build up on the following strokes. Does not improve much with addition
of oil. Use approximately three squirts from a plunger-type oiler.