Question

A cylinder power balance test is being performed on a vehicle with sequential port fuel injection. Two adjacent cylinders are under performing. Technician A says this could be caused by a restriction in the fuel injectors. Technician B says this could be caused by leaking secondary insulation. Who is correct

Answer 1

Neither A nor B

Step-by-step explanation:

A cylinder balance test is used to locate cylinders that are underperforming and leading to loss of power and unbalanced engine performance, by measuring the drop in RPM on each cylinder as compared to the other cylinders

The factors that result in under performing cylinders includes;

1) Problem with the ignition

2) Inadequate or restricted fuel delivery

3) Valve faults

4) Piston wear

Where adjacent cylinders are the cause for the lack of power, the likely causes includes;

1) Head gasket fault

2) Crack in the head

3) Crack in the block.