Engine; Engine Tune-Up; Spark Plug Removal; Test Compression - Chevrolet 10 1971 Series Chassis Service Manual

E ngine T u n e - U p ......................................................................................6-1
E ngine M e c ha n ic al (In L i n e ) ............................................................. 6-14
G e n e ral D e s c r i p t i o n .............................................................................
M e c h a n ic al Checks and A d ju s tm e n ts ...................................................6-1
Sp ark P lu g R e m o v a l......................................................................... .....6-1
Test C o m p r e s s io n .............................................................................
Se rv ice and In s ta ll Sp ark P lu gs
Se rv ic e Ig n itio n S y s t e m ................................................................... .....6-2
Se rv ice B a tte ry and B a tte ry C a b le s ................................................6-4
S ervice D e lc o tro n and R e g u la to r . . . . ..........................................6-5
S e rv ic e B e l t s ......................................................................................
S ervice M a n ifo ld H eat V a l v e ....................................................... .....6-5
T ighten M a n i f o l d ............................................................................... .....6-5
S e rv ic e Fuel L in e s and F ue l F i l t e r ........................................... .....6-6
S e rv ic e C o o lin g S y s te m .........................................................................6-6
S e rv ic e C ra n k c as e V e n t i l a t i o n .................................................... .....6-6
Choke A d ju s tm e n t.....................................................................................6-7
The engine tune-up is important to the modern auto­
motive engine with its vastly improved power and per­
formance. Emission system requirements, interrelated
system functions, improved electrical systems and other
advances in design, make today's engines more senstive
and have a decided effect on power, performance and fuel
consumption.
It is seldom advisable to attempt a tune up by correction
of one or two items only. Time will normally be saved
and more lasting results assured if the technician will
follow a definite and thorough procedure of analysis and
correction of all items affecting power, performance
and economy.
The tune-up will be performed in two parts. The first
part will consist of mechanical checks and adjustments;
the second part will consist of an instrument checkout
MECHANICAL CHECKS A N D ADJUSTMENTS

Spark Plug Removal

Remove any foreign matter from around spark plugs
by blowing out with compressed air, then disconnect
wires and remove plugs.
SECTION 6

ENGINE

CONTENTS OF THIS SECTION
Page

ENGINE TUNE-UP

INDEX
Page
6-1
6-1
................................................. .....6-2
6-5
GENERAL DESCRIPTION
E ngine M e c ha nic al ( V 8 ) ...................................................................... 6-26
Special T o o ls ...............................................................................................6-39
In s tru m e n t C h e c k - O u t ..........................................................................6-7
In s tru m e n t H o o k - U p ......................................................................... 6-7
Check and A d ju s t D w e ll....................................................................6-7
C heck Dw ell V a r i a t i o n ................................................................... 6-8
Check and A d ju s t T im in g ................................................................ 6-8
A d ju s t Id le Speed and M i x t u r e .................................................... 6-8
A d d itio n a l Checks and A d j u s t m e n t s ..............................................6-11
C y lin d e r B alance T e s t ....................................................................6-11
B a t t e r y .................................................................................................. 6-11
I g n i t i o n .................................................................................................. 6-11
C a r b u r e t o r ............................................................................................ 6-12
F uel P u m p ............................................................................................6-12
C ooling S y s te m ......................................................................................... 6-12
C y lin d e r H ead T orque and V alve A d ju s tm e n t.........................6-13
that can be performed with any one of the units of service
equipment available for this purpose. Always follow the
instructions provided by the manufacturer of the par­
ticular equipment to be used.
Additional checks and adjustments are included in the
latter part of this section for use as required. Many of
these operations can be used to isolate and correct
trouble located during the tune-up. Where conditions
are uncovered requiring major corrective action, refer
to the appropriate section of this manual or the Chassis
Overhaul Manual for detailed service information.
Typical illustrations and procedures are used except
where specific illustrations or procedures are necessary
to clarify the operation.
operations are used for clarification, however, all oper­
ations can be performed on the vehicle.
Test Compression (Fig. 1)
The compression check is important because an engine
with low or uneven compression cannot be tuned success­
fully. It is essential that improper compression be cor­
rected before proceeding with the engine tune up.
Page
Page
Illustrations showing bench
10-30 CHEVROLET TRUCK SERVICE MANUAL