Ranger 2WD V6-245 4.0L (1990)
Spark Plug: All Technical Service Bulletins
Engine - Loss of Power At High Engine Speeds
Article No.
92-3-8
01/29/92
LOSS OF POWER - 4.0L - AT HIGH ENGINE SPEEDS BETWEEN 3800 AND 4700 RPM - CANADIAN VEHICLES
LIGHT TRUCK:
1990-92 RANGER
1991-92 EXPLORER
ISSUE:
A loss of power may occur at engine speeds between 3800 and 4700 RPM under wide open throttle. After several months use, this can be caused by an
interaction between MMT (octane enhancer additive in Canadian fuel) contaminated spark plugs and the EDIS (Electronic Distributorless Ignition
System) module. A check engine light concern may be present with Self-Test Codes 18 (212 three digit code) and 45 in continuous memory.
ACTION:
If service is required, confirm the concern and, if necessary, replace the EDIS module and spark plugs. Refer to the following procedure for service
details.
1.
Confirm the customer concern by accelerating the vehicle at wide open throttle from 3000 RPM to 4700 RPM with the transmission in second
gear.
^
If the vehicle exhibits a loss of power (caused by fuel shutoff of one of the fuel banks) in this RPM range, follow Steps 2 and 3.
^
Otherwise, follow the Powertrain Control/Emissions Diagnosis Manual's diagnostic procedures.
NOTE:
FUEL SHUTOFF (REV. LIMITER) AT 4850 RPM FOR AUTOMATICS AND 5200 RPM FOR MANUAL TRANSMISSIONS IS NORMAL
AND SHOULD NOT BE CONFUSED WITH THIS CONCERN.
2.
Replace all the spark plugs.
3.
Replace the EDIS module (F1TZ-12KO72-B).
NOTE:
THIS MODULE WILL ELIMINATE THE PREMATURE FUEL SHUTOFF CONCERN. THE RED DEPOSITS ON THE SPARK PLUGS WILL
STILL OCCUR AFTER TIME. THIS IS CONSIDERED NORMAL FOR THIS TYPE OF FUEL.
PART NUMBER
PART NAME
CLASS
F1TZ-12K072-B
EDIS Module
B
AWSF42C
Spark Plug (Pkg / 10)
BG
AWSF42P
Spark Plug (Pkg / 10)
B
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under Bumper To Bumper Warranty Coverage For 1992 Models, Basic Warranty Coverage, Emissions Warranty
Coverage
OPERATION
DESCRIPTION
TIME
920308A
Replace Spark Plugs And
1.3 Hr.
EDIS Module
DEALER CODING
BASIC PART NO.
CONDITION CODE
12K072
08
OASIS CODES: 614000, 614500
