Engine - Lack of Power, Stalls, Bucking, and Jerking

Group: 24

Number: 93-07

Date: November 15, 1993

Subject:
Lack of power, Digifant engines

Model(s):
Fox from m.y. 1991 Vanagon from m.y. 1985
Golf/Jetta/Cabriolet from m.y. 1985

Condition

After one half to two hours driving at a constant speed, the vehicle lacks power, cuts-out or stalls, often accompanied by bucking or jerking.

In all cases the vehicle will restart immediately. The condition may not recur for several weeks or months. Subsequent service inspections produce inconclusive results.

Some Mass Air Flow Sensors can have a vibration resonance of the metering potentiometer wiper during an extended drive at constant speeds. The resonance causes the Mass Air Flow Sensor to supply an intermittent signal to the ECM. The ECM will then default to a "no load" condition and reduce the injection time.

Service

Part No. 025 906 302 A, is available to resolve this condition.

- Remove harness connector from Mass Air Flow Sensor

- Install converter assembly, Part No. 025 906 302 A, between harness and Mass Air Flow Sensor

CAUTION

Part numbers are for reference only. Always check with your Parts Department for the latest parts information

Note
If customer complaints persist after performing the above repair, contact your Zone Product Support Specialist (TSM in Canada).