Burn Time per Cylinder

This test possible only with Bear engine analyzer

This test is intended as an initial measurement similar to the idle quality test. Positive or negative variations, which always occur at the same cylinder, indicate a problem in the ignition system which will not always necessarily result in an engine speed drop. However, engine missing may occur at higher mileage.

Major positive or negative variations may be caused by carbon fouled spark plugs (e.g. short-distance driving). The vehicle should be driven for a longer distance to obtain a more exact diagnosis.

The variations shown in the table do not result in an unacceptable engine speed drop.

NOTE: Burn time per cylinder, Engine 104/111 HFM-SFI can be tested with HHT (Mercedes Hand-Held Tester) starting 01/94.

Table Idle Quality:

Scope Pattern:

a. Engine speed drop caused by preceding cylinder
b. Defective cylinder
c. Ignition malfunction caused by carbon or oil fouled spark plug. Possible defective insulation on secondary side.

Variations > ± 0.5 ms per cylinder should be confirmed by additional measurements such as oscilloscope and secondary ignition system table.