K 20 P/U 4WD V6-262 4.3L (1985)
Throttle Opener/Kicker Control: Technical Service Bulletins
Throttle Kicker - Revised Checking Procedure
Number: 86-99
Section: 6C
Date: JUNE, 1986
Subject:
THROTTLE LEVER ACTUATOR (THROTTLE KICKER) CHECKING PROCEDURE
Model and Year:
1985-86 C, K, G AND P MODELS WITH 4.3L, 5.0L, 5.7L ENGINES AND 1985 M VAN WITH 4.3L ENGINE
TO: ALL CHEVROLET DEALERS
A change has been made in the Throttle Lever Actuator (Throttle Kicker) Checking Procedure found in the 1985 and 1986 Light Duty Truck Service
Manuals. The current checking procedure, found in sections 6E8-109 (1985) and 6E8-105 (1986), does not differentiate between the V6 and V8 engines.
This may lead to unnecessary throttle kicker replacement on the V6 engine.
The throttle kicker used on certain Federal and California V6 engines is used to maintain a stable idle speed under varying engine load conditions. It
operates on the manifold vacuum available at idle and does not have an internal plunger return spring, but instead relies on throttle return spring pressure
to retract the plunger. The California HD V8 engines (Codes M and W) use a throttle kicker for decel emission control, and operates on higher decel
manifold vacuum. The kicker designed for these applications uses an internal plunger return spring that causes the plunger to retract automatically when
vacuum is released. These differences in design necessitate different checking procedures.
The current checking procedure in the 1985 and 1986 Light Duty Service Manual is correct for the California HD V8 engines. An additional procedure
is required for the Federal and California V6 engines (listed below).
THROTTLE KICKER CHECKING PROCEDURE (V6 FEDERAL AND CALIFORNIA EMISSIONS - ENGINE VIN CODE N)
1.
With engine off (not running), hold throttle half way open to allow throttle kicker plunger to fully extend for testing.
2.
Use J-23738-A or BT-7517, hand operated vacuum pump to apply 20" Hg (68 kPa) vacuum to the throttle kicker.
^
Apply finger pressure to the plunger to see if it has extended fully. If not, replace throttle kicker.
^
Observe vacuum gauge: Vacuum should hold for at least twenty seconds. If not, replace throttle kicker.
3.
Release vacuum to the kicker.
^
Apply finger pressure to the plunger, to move it to its retracted position. If plunger will not retract, replace the kicker.
!!!! IMPORTANT !!!!
THE THROTTLE KICKER USED ON THE V6 ENGINE BY DESIGN DOES NOT HAVE AN INTERNAL PLUNGER RETURN SPRING. WHEN
VACUUM IS RELEASED FROM KICKER, THE PLUNGER WILL NOT RETRACT ON ITS OWN. THIS UNIT REQUIRES THROTTLE LEVER
PRESSURE TO RETRACT THE PLUNGER.
