Digital Mode

When using the Mcat Compression Tester in digital mode measurements are displayed on the unit itself in the display windows.
In this mode there needs to be a minimum of 0.49MPa (5 kg/cm² or 71PSI) of compression for the unit to measure correctly.

1. When using on a fuel injected car first remove the EGI fuse, to prevent entering the engine.
Check the service manual if you are unsure.[Important]
This is to prevent the vehicle from starting during measurement (EFI cars).
If the engine starts during measurement, the sensor will not only be damaged, but detonation may occur and it can damage the engine.

* Turn off the fuel pump (fuse is extracted), to prevent fuel going to the engine
* Start the vehicle or crank it over to remove any residue fuel in the system. If the car starts let it idle until it stops (Especially carburetor engine) , turn off the ignition
* Remove plug cords for safety but leave the plugs in.

2. Remove the plug of cylinder to measure (by the side of "T" of housing on rotary engine).

3. Screw the plug hole adaptor into the plug hole until the o-ring is in contact with the bottom of plug hole and tighten approximately half a revolution.


4. Slide the mode switch to "Digital" side. ( In case of Comp-07S, "Original" side)


5. Clip the power supply cables to the battery (DC12V)
Clip red to "+", and black to "-".
.

6. Select unit display mode switch to (1)Pa, (2)Kg/cm² or (3)PSI.
The change of a measurement unit should switch slide by sharp-end tool like a ball-point pen.
* No position (3)PSI in Comp-07S

7. Connect the sensor cable to the adapter.


8. Connect the sensor cable to the tester then press the RESET switch.


9. "8"s are displayed on all display windows for approx 1 second.


10. When "000" are displayed in the RPM window, fully depress the clutch and accelerator then begin cranking.
Making sure the gear selector is in "neutral" at MT vehicle or "park" at AT.
Count down "5"to"0" in RPM window while measuring.

11. Measurement is complete when the results are displayed - stop cranking.


12. To measure the other cylinder(s) or rotor(s) on the engine complete the above steps from step 8 after re-installing the adaptor as in step 2.
13. Once complete disconnect the sensor cable from the adaptor.
14. Remove the adaptor and re-install any plugs and associated plug cords.
15. Remove the power supply cables.
16. Re-install the EGI fuse if you have removed it and prime the fuel system - check the service manual if unsure.

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