Engine Stalling Condition

Engine stalling condition

Symptom

A momentary loss of engine power. or stalling; the engine restarts immediate. The CHECK ENGINE MIL remains OFF and NO DTC is flagged.

Use this procedure to diagnose and repair the stalling condition. All of the steps in the procedure must he completed.

Diagnostic Notes

1. Stalling can occur from high tension tracking caused by dirt accumulateing on the ignition coil high tension (HT) tower.
2. 1993 MY vehicles - Hella relays are marked with a manufacturing date code. The first Two digits indicate the week; the last digit indicates the year. Code 183 indicates the 18th week of 1993.

3. Engine fueling correction (dynamic) can he monitored by using JDS or PDU to read the oxygen sensor feedback voltage (HO2SFB). If the feedback voltage is between 1 and 4 volts. the fueling is normal. If the feedback voltage stays below 1 volt, look for causes of rich running (DTC 23); if the feedback voltage stays above 4 volts. look for causes of lean running (DTC 26).

Oxygen Sensor Feedback:

Oxygen Sensor Voltage Trace:

During closed loop fueling. the oxygen sensor raw voltage (signal voltage to the ECM) normally swings between 0.2 and 0.8 volt. If the oxygen sensor becomes contaminated or the heater is inoperative, the sensor can he "lazy". A lazy sensor may show a voltage swing of 0.3-0.7 volt or even less. The oxygen sensor raw voltage can be monitored using PDU (HO2 S RAW).
4. During 1994 MY, gold-plated connector pins were introduced to prevent corrosion and resistance build-up. The gold-plated pins can be identified by their color.

CAUTION: Tin-plated pins and gold-plated pins must not be matched; they are not compatible.

Diagnostic flow chart

h 7 Flow Chart: