Hesitation And Stumbling - Engine Temperature Sensor (ACU0402AP)

Publication date: 1995-03-01
Reference number: ACU0402AP

HESITATION AND STUMBLING - ENGINE TEMPERATURE SENSOR

TECHNICAL INFORMATION TIP

Reference Number(s): ACU0402AP, Date of Issue: March, 1995

HESITATION AND STALLING

YEAR(S): 1986-89

MANUFACTURER: Acura

MODEL(S): Legend

DATE OF ISSUE: March, 1995

ISSUE & TIP

Hesitation and stalling due to an excessively rich fuel mixture during off-idle conditions on 1986-89 Acura Legend models may be caused by a faulty TW sensor (Acura's name for the engine temperature sensor). The vehicle we were repairing had no Check Engine light or stored trouble codes.

Using an emissions analyzer, we checked the vehicle's emissions at idle. Everything was fine until the gas pedal was feathered, at which point the emissions readings would skyrocket. We suspected the TPS, but it checked out fine.

After a lot of lost time, we replaced the TW sensor. The sensor was going open under some conditions, fooling the ECU into thinking the engine was cold. The rich mixture supplied by the ECU in response to these false signals caused the engine to run too rich. This lead to the hesitation and stalling symptoms.

Courtesy of Import Service Magazine

with thanks to:

Steven Kirgan

Hondamen

Copiague, New York

REFERENCE NUMBER

ACU0402AP

NOTE: This information has been obtained from sources generally believed to be reliable. Use your own judgment before relying on this data. Neither the suppliers of these Technical Information Tips, nor lemon-25 Repair Information Company, LLC, guarantees or assumes responsibility for data accuracy or completeness, nor is liability assumed by the suppliers of these Technical Information Tips or lemon-25 Repair Information Company, LLC, for any claims or damages resulting from the use of this information.