F0:Data List - Test Step 27 O2 Integrator Opel Calibra I

F0:DATA LIST

No.

Engine running at idle speed, operating temperature

Note:

The air/fuel mixture correction of the oxygen sensor regulation can be evaluated using the 02 INTEGRATOR.

If, for example, the air/fuel is too lean, the 02 INTEGRATOR value and thus the injection period is increased in steps until the oxygen sensor signals that the mixture is too rich.

The 02 INTEGRATOR is then decreased again in steps and thus the injection period shortened until the oxygen sensor indicates that the mixture is too lean (closed loop only).

02 INTEGRATOR = 128 means either: stochiometric air/fuel ratio of approx. 14.7 parts by volume air to one part by volume fuel; i.e. for the combustion of each fuel particle, there is one air particle available.

or: the circuit has been opened by the control unit, as a fault is present (e.g. oxygen sensor defective) or the conditions for closed loop have not yet been attained.

02 INTEGRATOR < 128 means: system becomes leaner, mixture is too rich (injection period is reduced).

02 INTEGRATOR > 128 means: system becomes richer, mixture too lean (injection period is increased).

Note:

The 02 INTEGRATOR affects the injection period and thus also the amount of fuel injected. As the amount of fuel depends on the fuel pressure, incorrect fuel pressure can be detected as follows:

· Fuel pressure too high: 02 INTEGRATOR and thus injection period is reduced in steps (system becomes leaner).

· Fuel pressure too low: 02 INTEGRATOR and thus injection period is increased in steps (system becomes richer).

In order to evaluate a deviation of the 02 INTEGRATOR value, the values of the 02 BLM IDLE THR. correction and 02 BLM PART THR. correction must also be evaluated.

Possible interrelationships if nominal values are not attained:

02 INTEGRATOR < 123 and 02 BLM IDLE THR. < 80 : system becomes leaner, mixture too rich.

02 INTEGRATOR < 123 and 02 BLM PART THR. < 124 : system becomes leaner, mixture too rich.

02 INTEGRATOR > 133 and 02 BLM IDLE THR. > 127 : system becomes richer, mixture too lean.

02 INTEGRATOR > 133 and 02 BLM PART THR. > 131 : system becomes richer, mixture too lean.

Measured value < 123 steps (system becomes leaner, mixture too rich)

· Check fuel pump pressure (observe safety regulations)

· Install pressure gauge in feed and return lines

· Engine running at idle speed

· Remove vacuum hose from fuel pressure regulator.

Feed pressure:

2.2 to 2.7 bar

Return pressure:

0.3 to 1.5 bar

Feed pressure:

3.0 to 3.5 bar

Return pressure:

· Fuel pressure too high

· Pressure regulator defective

· Return line blocked or kinked

· Baffle plate in fuel tank blocked

· Vacuum hose to pressure regulator leaky

Further causes of fault:

· Tank vent valve constantly open

· Injection valves leaky

· Temperature sensor P12 defective (see test step 06)

· Oxygen sensor P32 defective (see test steps 25/26)

· Control unit K61 defective

Measured value > 133 steps (system becomes richer, mixture too lean)

· Check fuel pump pressure (observe safety regulations)

· Install pressure gauge in feed and return lines

· Engine running at idle speed

Feed pressure:

2.2 to 2.7 bar

Return pressure:

· Fuel pressure too low

· Fuel pump defective

· Baffle plate in tank loose

· Fuel filter dirty

· Dirty pre-filter

Continued

· Remove vacuum hose from fuel pressure regulator

Feed pressure:

3.0 to 3.5 bar

Return pressure:

· Check fuel pump supply quantity (see Technical Data)

Further causes of fault:

· Injection valve defective or dirty

· Poor fuel quality

· Intake system leaky (air leak)

· Temperature sensor P12 defective (see test step 06)

· Oxygen sensor P32 defective (see test steps 25/26)

· Exhaust system leaky (in front of oxygen sensor)

· Control unit K61 defective