Econoline E350 1 Ton V8-5.4L Prop SOHC VIN Z (1998)
Go to the Oscilloscope Tool and select Channel 3, then select Auto, then select COP_STRESS_TEST_RED. This pre-configured setting will zoom-in on
the peak firing of the coil being tested. Start the engine and be sure the coil is not sparking to any surface. If the coil is sparking to other surfaces, turn the
engine off immediately and readjust the coil so it cannot spark to any other surface. Restart the engine and touch the Red Man icon to start the
oscilloscope. All settings are pre-configured and no adjustments are necessary. Compare the waveform you get with the examples provided in Figures 7,
8, and 9). Figure 7 is a good waveform. If your waveform is similar to Figure 7 the coil is working correctly. Suspect the spark plug.
Figure 8 and Figure 9 are examples of problem coils. Replace the coil if the waveform is similar to Figures 8 or 9. The coil is causing the misfire when
the peak firing appears like those shown in Figures 8 and 9. Notice the difference in the peak-firing signal when compared to the good peak signal in
Figure 7.
Figure 9 shows a more dramatic fault in the peak failure.
Most root causes of misfire issues can be identified quickly using the steps outlined above. Some misfire issues can be difficult making the oscilloscope
an important part of your diagnostic toolbox.
OTHER APPLICABLE ARTICLES: 05-13-4
WARRANTY STATUS: Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
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