Engine Controls - New ECM Reduces Spark Knock
90nissan07Classification: Section: Automatic
AT90-005 Transmission
Reference:
TECHNICAL BULLETIN NTB90-097
Models:
1990 300ZX [Z32] Date:
November 8, 1990
ENGINE DETONATION
(SPARK KNOCK)
SERVICE INFORMATION:
On some 1990 non-turbo 300ZX vehicles equipped with automatic transmissions, customers may complain of engine detonation [spark knock] during vehicle operation. A countermeasure Electronic Control Unit (E.C.U.) is now available that reduces engine detonation.
SERVICE PROCEDURE:
When a customer complains of this incident, verify the following:
^ that UNLEADED PREMIUM gasoline has been used in the vehicle.
^ that the engine is tuned to specification [e.g., engine timing, idle speed, throttle valve switch, etc].
^ that the incident occurs under the following conditions:
1. Intake manifold vacuum is between 5.91-7.87 in.Hg (150-200 mmHg]. 2. Engine speed is approximately 2000 rpm.
3. Vehicle speed is approximately 60 mph.
If these points are confirmed, install the new E.C.U. into the vehicle. Confirm that the incident has been eliminated to the customer's satisfaction.
COUNTERMEASURE FORMER
APPLIED MODEL PART NUMBER PART NUMBER
Federal -
Automatic Transmission 2371M-40P60RE 23710-30P13
California -
Automatic Transmission 2371M-40P65RE 23710-30P18