Safari Van M V6-262 4.3L (1985)
Idle Speed: All Technical Service Bulletins
Campaign - Cold Idle Speed Reduction, Wheel Spin on Ice
GMC NUMBER:
85-T-107
GROUP:
5 - Brakes
DATE:
August, 1987
CORPORATE
NUMBER:
565002
SUBJECT:
COLD IDLE SPEED REDUCTION
MODELS:
1985 M VANS WITH 4.3L ENGINE AND AUTOMATIC TRANSMISSION
Some customers may experience a condition immediately after cold vehicle startup where, by applying the brake pedal, they are unable to completely
stop the rear wheels from turning on icy surfaces. Variables such as rear axle ratios and higher engine rpm while the vehicle is in the cold idle mode can
result in increased torque to the rear wheels. These variables, in conjunction with a lightly loaded rear axle, can increase the pedal effort required to stop
the rear wheels from spinning on ice when the vehicle is placed in gear. This condition can be effectively addressed by using the service procedure to
reduce the cold idle speed of the engine.
SPECIAL POLICY ADJUSTMENT
Should this condition occur, GMC Truck Division will repair involved vehicles at no charge for a period of five years, regardless of mileage from the
date the vehicle was originally placed in service. This "SPECIAL POLICY ADJUSTMENT BULLETIN" should be filed in the three ring binder
furnished each dealer by General Motors.
OWNER NOTIFICATION
Owners of vehicles involved in this SPECIAL POLICY ADJUSTMENT will be notified by GMC Truck (see copy of owner letter included with this
Bulletin).
SERVICE PROCEDURE - 1985 MODEL 4.3L CARBURETED ENGINE
Reduce cold idle speed to 1600 rpm.
1.
Remove dash extension..
2.
Remove engine cover.
FIGURE NO. 1
3.
Install tachometer. The tachometer (tach) terminal is next to the engine control switch (bat) connector on the distributor cap (Reference Figure No.
1).