GMC 4000 Series Service Manual page 329

Sec. 6M
Page 318
FUEL SYSTEM— GASOLINE ENGINES
Figure 2 — Accelerator Linkage ("E" and "S " Models
with In-Line Engine)
"E" A N D "S" MODELS WITH
IN-LINE ENGINE
(Refer to Figure 2)
1. Disconnect pull-back spring from throttle
lever, then disconnect relay rod from relay lever.
2. Block accelerator pedal down against floor
mat or pedal stop, hold bell crank in full throttle
position and adjust swivel until relay rod fits freely
into relay lever.
3. Release accelerator pedal and connect pull­
back spring to throttle lever.
CONVENTIONAL CAB MODELS
WITH V6 ENGINE
(Refer to Figure 3)
1. Disconnect pull-back spring from carbur­
etor.
2. Loosen jam nut on relay rod and disconnect
relay rod from throttle lever.
Figure 3 — Accelerator Linkage (Models
Equipped with V6 Engines)
G M C S E R V I C E M A N U A L
floor mat; then hold carburetor throttle lever in
full throttle position and turn relay rod until end of
rod fits freely into relay lever. Tighten jam nut on
relay rod firmly.
back spring to carburetor.
ator linkage pull-back spring.
Place a .54" spacer between accelerator pedal and
floor mat.
erly, the accelerator pedal will just contact the
spacer when pedal is held down tightly by hand.
necessary to shorten telescopic linkage at relay
lever. If pedal can be held closer to floor when
spacer is removed, it will be necessary to lengthen
telescopic linkage at relay lever.
forward and remove trunnion on telescopic rod at
relay lever. Loosen trunnion jam nuts, adjust trun­
nion; then tighten jam nuts and install trunnion on
relay lever.
spring, then lock cab down in normal operating
position. Remove spacer from under accelerator
pedal and check operation of accelerator linkage.
fully open (vertical) when choke control knob is
pushed in. Choke setting can be changed as follows:
instrument panel, then move choke lever to fully
open position and tighten screw which secures
choke wire to lever on carburetor.
choke valve closes completely as knob is pulled
out. Reposition choke housing in clamp if there is
interference before choke valve is completely
closed.
covered in this section.
ment and to be sure pull-back spring returns ac­
celerator linkage to idle position.
ing is clamped securely at bracket.
3. Block accelerator pedal down firmly against
4. Release accelerator pedal and connect pull­
TILT CAB MODELS
(Refer to Figure 4)
1. Tilt cab forward and disconnect acceler­
2. Return cab to normal operating position.
3. When accelerator linkage is adjusted prop­
4. If pedal does not contact spacer, it will be
5. To adjust linkage at relay lever, tilt cab
6. Connect the accelerator linkage pull-back
M A N U AL CHOKE CONTROL
Adjust manual choke control so choke valve is
1. Loosen choke wire screw at carburetor.
2. Position choke control knob 1/8-inch from
3. Check operation of choke to make sure
NOTE: Adjustment of fast idle mechanism is
HAND THROTTLE ADJUSTMENT
1. Check accelerator linkage for free move­
2. Check to see that hand throttle wire hous­