What this tool is used for
- Comparing cylinder cranking pressure under consistent conditions
- Supporting mechanical-condition diagnosis
- Directing follow-up leak-down, timing, or valve testing
A tool produces useful evidence only when its rating, setup, test conditions, and reference limits are correct.
- 01ChooseComparing cylinder cranking pressure under consistent conditions
- 02Set upDisable fuel and ignition using the exact procedure / Confirm battery condition, cranking speed, throttle requirements, and adapter fit
- 03MeasurePrepare the engine and record test conditions / Install the correct adapter without damaging threads
- 04InterpretUniversal pressure expectations are unreliable
- 05RecordPreserve setup, conditions, result, and next test
Follow the sequence, stop when evidence changes the path, and verify the exact vehicle information before acting.
Before you use it
Disable fuel and ignition using the exact procedure
Confirm battery condition, cranking speed, throttle requirements, and adapter fit
Protect the spark-plug threads and keep debris out of the cylinder
A test-first working method
Prepare the engine and record test conditions
Preserve the conditions and result so the measurement can support—or reject—the current diagnostic theory.
Install the correct adapter without damaging threads
Preserve the conditions and result so the measurement can support—or reject—the current diagnostic theory.
Crank each cylinder consistently
Preserve the conditions and result so the measurement can support—or reject—the current diagnostic theory.
Compare patterns with exact service information and follow-up tests
Preserve the conditions and result so the measurement can support—or reject—the current diagnostic theory.
What the tool cannot prove by itself
- Universal pressure expectations are unreliableInterpret the result with circuit, system, operating-condition, and source context.
- Unequal cranking speed or test setup can distort comparisonInterpret the result with circuit, system, operating-condition, and source context.
- A compression result alone may not identify where sealing is lostInterpret the result with circuit, system, operating-condition, and source context.
Safety boundary
Disable starting safely
Prevent ignition, fuel delivery, and unexpected engine start. Keep tools, leads, and clothing clear of rotating parts.