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Midland, MI 48640
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Methods to use the FirstLook ADS ES 100 to diagnose diesel engines
1. Dynamic Compression Test: Purpose of test is to determine the base condition of valves and compression.
- Scope setup: 1 volt peak-to-peak and 1 second full screen sweep.
- Warm engine to operational temperature. Disable fuel and crank engine over with sensor in tailpipe.
- Adjust voltage scale for best output on scope.
The waveform below shows the output of a 4 cylinder Volvo truck engine.
This waveform shows an engine in very good condition.
2. Crankcase Idle Test: Determine if problems are more extensive than just valves or gaskets. A bad piston will leak pressure into the crank case of the engine. When used over time, this test can also determine ongoing wear and piston blow caused by engine wear.
- Scope Setup: 1 volt peak-to-peak and 200ms full screen sweep.
- Insert sensor into oil dipstick tube using supplied adaptor, start engine and observe waveform at engine idle.
- Adjust voltage scale for best output on scope.
The observed waveform below shows a blown cylinder in a 6.5 V8 GM diesel engine.
3. Tailpipe Idle Test: If Dynamic Compression test and Crankcase Idle test are good, this test will give us a good idea of combustion efficiency which is directly related to injector problems in a diesel engine.
- Scope Setup: 1 volt peak-to-peak and 200ms full screen sweep.
- Insert sensor into tailpipe and allow engine to come up to operational temperature and observe waveforms.
- Adjust voltage scale for best output on scope.
The observed waveform below shows a 6.5 GM diesel engine with 99,000 miles on it in reasonably good condition. Test window of 500 ms allows for multiple cycles and comparison of cylinder events.
