FirstLook Engine Diagnostic Pulse Sensor

Case Study: Diesel Engine Rebuilding

Read how the Michigan National Guard uses a 4-channel Pico scope with the Senx Firstlook to verify their rebuilt desiel engines are ready for the field. The engines are tested under three conditions:
- cold cranking with no fuel at about 300 RPM,
- warm idle at about 750 RPM,
- and with a braking load at about 1500 RPM.

"SenX Technology, and Pico Technology have assembled a mechanical testing solution that provides the Michigan Army National Guard a quantum leap in the speed and accuracy...." Read more...

Case Study: Worn Cam and Lifter in a Safari Van

Click here to view an ad showing before and after waveform samples from a Pico scope!

The Firstlook looks at dynamic pressure changes and is much more sensitve than any known absolute vacuum sensor. It can be used on the fuel rail pressure regulator to watch the injectors operate, it can be used in the exhaust to follow the exhaust valve cycle, it can be used in the oil-fill dipstick hole to observe whether there is cylinder blow by from ring or piston problems...some even use it to find leaks in tire rim seals!

Case Study: Smoothing A Noisy Signal

The Firstlook kit includes a Vacuum Adapter. Insert this Vacuum Adapter into  the exhaust probe to 'smooth' the signal to create a waveform that is easier  to understand. Read the details!

This technique is most effective on exhaust systems that contain many sharp  angles and bends.

Diesel: Normal output no problems. Cumming 6 Cylinder Diesel Engine at 1250 RPM.

Diesel: Normal output no problems. Waveform taken from a Cummings 6 Cylinder Diesel with Turbo Charger 600 rpm.

Fluke 190c series

Honda Accord 2002
Test Point: fuel pressure regulator
Test Condition: 4 Cylinder engine with a fuel rail test through the pressure regulator.

Fluke 98

Cadillac De Ville, 2003, 4.6L
Mileage: 2320
Test Point: Exhaust
Test Condition: Cadillac DeVille 2003 Northstar Engine cold during power brake test at 1500RPM with dual exhaust pipes.

Gasoline: 1 cylinder of a Honda Accord 4 cylinder engine at 2400 rpm. Redline is Sparkplug Trigger Signal.

Gasoline: Note dropout in exhaust pattern. GM 3800 6 cylinder engine number #3 injector not working.

Gasoline: This was taken using the scope trigger mode. Cold Crank 3800 GM 6 cylinder Engine in good condition.

Pico Scope

Connect the First Look Sensor to Channel A on the PicoScope using the 25ft BNC to BNC cable (included with FirstLook) then attach the Firstlook sensor to the exhaust pipe.

Now connect the Secondary Ignition pick-up Lead to Channel B of the scope and attach the clamp to the cylinder 1 plug lead. Once you have disabled the fuel system (may not be possible on a carburated engine), crank the engine until the display pattern stabilizes. You can adjust the timebase and voltage scales to achieve best signal display.

This test is useful when it is desirable to obtain cylinder specific data without the engine running. You will need to disable the fuel system to perform this test. This test allows us to look at the action of the valve train and cylinders, exhaust valve action per cylinder and problems with the head or head gaskets may be assesed.

This waveform shows a consistent signal pattern on Channel A (Red) as triggered against Channel B (Blue) on the same time line. Cursor lines are added to show trigger reference (sparkplug 1) and show the time between trigger events. We can use this information to determine the approximate cranking speed of this engine.

Vetronix MTS 5100

Cadillac 3.2
Test Point: Exhaust
Test Condition: Engine at 1200RPM during power brake test. Engine would hardly run with only 3 cylinders firing.

FAQ

1. What type of lab scope do I need to use the )))FirstLook sensor?
Most modern dual trace lab scopes will work with this sensor. The lab scope needs to have triggering ability and cursors for pattern measurement. The triggering allow you to get cylinder specific information as it relates to a specific event in the engine i.e.( firing of number one spark plug). The cursors allow you to dissect the pattern and find which cylinder has the problem.

2. What information can the )))FirstLook sensor give me?
Basically, the sensor, because of it's live unaltered signal, can look at valve operation, cylinder efficiency, fuel injector operation, and overall engine operation.

3. Why is the information the )))FirstLook sensor gives important to diagnostics?
All the information gathered by the )))FirstLook is the same information the vehicle computer looks at to make changes in the performance of the engine. If the base engine functions are not in proper order, the computer
in the vehicle can give erroneous information and false diagnostic trouble codes which can result in wasted time and money. (Have we ever purchased a part that the vehicle did not need but a diagnostic chart led you in that direction?) In short if the base engine functions are not in proper working order all information given by the computer is tainted.

4. How to setup Scope for the )))FirstLook diagnostic sensor.
Cold Crank Test or Dynamic Compression Test.
1. Set scope for 1 second sweep total screen.
2. Set voltage range to AC and 1 volts plus and minus to start with.
3. Insert sensor into tailpipe and connect to diagnostic scope input channel.
4. Disable fuel or ignition so engine can be cranked but not started.
5. Crank engine over and observe waveform on scope.
6. Adjust voltage levels for maximum display on scope screen.

A good engine will always have a stable and repeatable series of waveforms.