1967 CHEVROLET CAMARO engine

SECTION 6M

ENGINE FUEL

CONTENTS OF THIS SECTION

Page

Carburetors 6M-1 Fuel Pumps .

Air Cleaners 6M-7 Special Tools
Page

6M-10

6M-12

CARBURETORS

INDEX

Page

General Description 6M-1

Service Procedures 6M-1

Preliminary Checks 6M-1

Idle Speed and Mixture Adjustment ........... 6M-1

Fast Idle Adjustment .................. 6M-3

Choke Adjustment 6M-3

Float Adjustment 6M-4
Page

Additional Adjustments 6M-4

Removal 6M-4

Test Before Installation 6M-5

Installation 6M-5

Fuel Filter Maintenance 6M-5

Choke Coil Replacement 6M-5

Throttle Linkage Adjustment . . 6M-6

GENERAL DESCRIPTION

Various carburetors (fig. lc) are used with Chevrolet,

Chevelle, Chevy II, Camaro and Corvette passenger

vehicles. These carburetors are designed to meet the

particular requirements of engines, transmissions and

vehicles, therefore carburetors that look alike are not

always interchangeable. (Refer to carburetor part num-

ber and/or specifications.)

Because many service procedures for the various

carburetors are similar, typical illustrations and pro-

cedures are used except where specific illustrations or
procedures are necessary to clarify the operation.

This section covers removal, installation and adjust-

ments (on engine) of carburetors. Also covered in this

section are maintenance procedures for choke coils,

throttle linkage and fuel filters. For carburetor .over-

haul procedures and additional adjustments (bench), re-

fer to Section 6M of the Overhaul Manual under the

carburetor being serviced.

Specifications for carburetors are located in the back

of this manual.

SERVICE PROCEDURES

Preliminary Checks

1.
Thoroughly warm-up engine. If the engine is cold,

allow to run for at least 15 minutes.

2.
Inspect torque of carburetor to intake manifold bolts

and intake manifold to cylinder head bolts to exclude

the possibility of air leaks.

3.
Inspect manifold heat control valve (if used) for free-

dom of action and correct spring tension.

Idle Speed and Mixture Adjustment (Except Air Injection

Reactor System)

NOTE:
This adjustment should be performed

with engine at operating temperature and park-

ing brake applied.

1.
Remove Air Cleaner.

2.
Connect tachometer and vacuum gauge to engine, then

set hand brake and shift transmission into neutral.

3.
As a preliminary adjustment, turn idle mixture

screws lightly to seat and back out 1-1/2 turns.

CAUTION: Do not turn idle mixture screw

tightly against seat or damage may result.

4.
With engine running (choke wide open) adjust idle
speed screw to specified idle speed, (automatic

transmission in drive, synchronized transmission in

neutral).

5. Adjust idle mixture screw to obtain highest steady

vacuum at specified idle speed.

NOTE:
On air conditioned vehicles, turn air

conditioning to the "on" position and hold the

hot idle compensator valve closed while adjust-

ing idle speed and idle mixture screws.

NOTE:
On Rochester BV carburetors the idle

mixture screw should be turned out 1/4 turn

from the "lean roll" position. The definition

of "lean roll" point is a 20 to 30 rpm drop

in engine speed obtained by leaning the idle

mixture.

6. Repeat Steps 4 and5 as needed for final adjustment.

NOTE:
If necessary, final adjustment of the \

carburetor may be made with the air cleaner

installed.

7. Turn engine off, remove gauges and install air

clearer.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL
6M-2

ROCHESTER
BV

IDLE

SPEED
IDLE

MIXTURE
ROCHESTER
2GV
HOLLEY 2300C

(PRIMARY)

IDLE

MIXTURE

SPEED
HOLLEY 2300

(SECONDARY)

IDLE IDLE

MIXTURE SPEED

MANUAL
CHOKE CART
R YF
AUTOMATIC CHOKE

IDLE

SPEED

IDLE

MIXTURE
IDLE

MIXTURE

IDLE

SPEED
ROCHESTER
4MV

IDLE

SPEED

IDLE

MIXTURE

SIDE INLET
HOLLEY
4150

CENTER INLET

IDLE

MIXTURE
IDLE

MIXTURE
IDLE

SPEED
HOLLEY
4160

IDLE

MIXTURE
IDLE

SPEED

APPLICATION

CARBURETOR

U
IN LINE

153

90
194

120
230

140
250

155
V-8

283

195
210
327

275 300 325 350
350

295
396

325 350
427

385 390 400 425 435

ROCH.
BV

1234

ROCH
2GV

1234

ROCH
4MV

1234
1-2

CARTER

YF
Man.

Auto.

2-4

1234

HOLLEY

4150
Side

Center

HOLLEY
4160

HOLLEY

2300
C Prim.

Sec.

Fig.
1C
—Carburetors

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL 6M-3

Idle Speed and Mixture Adjustment (With Air Injection

Reactor System)

The following is the recommended procedure for Air

Injection Reactor System equipped engines.

NOTE: This adjustment should be performed

with engine at operating temperature and parking

brake applied.

1.
Remove air cleaner.

2.
Connect tachometer to engine, then set hand brake

and shift transmission into neutral.

3.
As a preliminary adjustment, turn idle mixture

screws lightly to seat and back out 3 turns.

CAUTION: Do not turn idle mixture screw

tightly against seat or damage may result."

4.
With engine running (choke wide open) adjust idle

speed screw to specified idle speed. (Automatic

transmission in dirve, synchronized transmission in

neutral).

5.
Adjust idle mixture screw (turn in) to "lean roll"

position; then turn screw out 1/4 turn (1/4 turn

rich from "lean roll"). The definition of "lean

roll" point is a 20 to 30 rpm drop in engine speed,

obtained by leaning the idle mixture.

NOTE: On air conditioned vehicles, turn air

conditioning "OFF" on in-line, 283, 327, and'

350 cu. in. engines, and turned "ON" and hot

idle compensator held closed on 396 and 427 cu.

in. engines.

6. Repeat Steps 4 and 5 as needed for final adjustment.

NOTE: If necessary, final adjustment of the
carburetor may be made with air cleaner

installed.

7.
Shut down the engine, remove gauges and install air

cleaner. *

Fast Idle Adjustment

Rochester
4MV and Holley

With fast idle lever on high step of cam and choke valve

open (engine warm) set fast idle to give specified engine

rpm. Adjust sejrew on Rochester 4MV and bend fast

idle lever *pn Holley. .

Choke Adjustment

With Remote Choke (Fig. 2c)

1.
Remove air cleaner and check to see that choke

valve and rod move freely.

2.
Disconnect choke rod at choke lever.

3.
Check choke adjustment as follows:

On all except 275 and 300 h.p. 327 cu. in. engines,

hold choke valve closed and pull.rod up against stop.

The top of choke rod end should be 1/2-1 rod diame-

ter above top of hole in choke valve lever.

On 275 and 300 h.p. 327 cu. in. engines, hold choke

valve closed and push rod down against stop on ther-

mostat bracket. The top of the choke rod should be

1/2-1 rod diameter below the top of the hole in the

choke lever.

4.
If necessary, adjust rod length by bending rod at

offset bend. (Bend must be such that rod enters

choke lever hole freely and squarely).

5.
Connect rod at choke lever and install air cleaner.

With Manual Choke (Carter YF)

1.
Remove air cleaner.

CHOKE VALVE

COMPLETELY

CLOSED

PULL UPWARD ON

ROD TO END OF

TRAVEL

BEND ROD

TO ADJUST
ROD IN BOTTOM

OF SLOT

BOTTOM OF

ROD SHOULD

BE EVEN WITH

TOP OF

HOLE
CHOKE VALVE

CLOSED

BOTTOM OF

ROD SHOULD

BE EVEN WITH

TOP OF HOLE

TOP OF ROD

SHOULD BE EVEN

WITH BOTTOM

OF HOLE (CHOKE

CLOSED)

BEND ROD TO

ADJUST

PULL DOWNWARD'

ON ROD TO CON-

TACT STOP

L6 (TYPICAL)

[

V8 327-275 HP

V8 350-295 HP
BEND ROD

TO ADJUST

PULL UPWARD ON

ROD TO CONTACT

STOP ON BRACKET

ALL V8 (EXCEPT 327-275 HP

AND 350-295 HP)

Fig.
2C—Remote Choke Adjustment

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL 6M-4

Fig.
3C-Fuel Level Sight Plug

2.
Push hand choke knob in to within 1/8" of instru-

ment panel.

3.
Loosen choke cable clamp at carburetor bracket and

adjust cable through the clip until the choke valve

is wide open.

4.
Tighten cable clamp at carburetor bracket and check

operation of choke valve to ensure full closed and

wide open positions.

5. Install air cleaner.

Float Adjustment

Ho/fey (Model 4150
Center
Inlet & Model 2300)

1.
Remove air cleaner then remove the fuel level sight

plugs (Fig. 3c)

2.
With parking brake on, and transmission in neutral,

start the engine and allow it to idle.

3.
With the car on a level surface, the fuel level should

be on a level with the threads at the bottom of the

sight plug port (plus or minus 1/32 inch).

NOTE:
No float drop adjustment is required

on this carburetor.

4.
If necessary to adjust (either or both bowls), loosen

inlet needle lock screw and turn the adjusting nut

clockwise to lower or counter-clockwise to raise

fuel level, then tighten lock screw.

NOTE:
1/6 turn of adjusting nut equals ap-

proximately 1/16" fuel level change.

5. Allow a minute for fuel level to stabilize then re-

check the level at sight plug.

6. Readjust, if necessary, until proper level is obtained,

then install sight plug and air cleaner.

NOTE:
To assure proper secondary float level

setting it is advisable to accelerate primary

throttles slightly and hand operate secondary
throttle. This assures a stabilized secondary

fuel level.

Additional Adjustments

The following adjustments may be made without re-

moving the carburetor from the engine. For procedure

refer to Section 6M of the Overhaul Manual under the

carburetor being serviced.

Rochester BV

• Float

• Idle Vent

• Choke Rod (Fast Idle)

• Choke Vacuum Break

• Choke Unloader

Rochester 2GV

• Float

• Accelerator Pump

• Idle Vent

• Choke Rod (Fast Idle)

• Choke Vacuum Break

• Choke Unloader

• Secondary Throttle Opening

• Secondary Throttle Lockout

Rochester 4MV

• Float

• Accelerator Pumj)

• Idle Vent

• Air Valve

• Choke Rod

• Choke Vacuum Break

• Choke Unloader

• Air Valve Lockout

• Secondary Opening

• Secondary Lockout

Carter YF

• Float

• Idle Vent

• Choke Rod (Fast Idle)

• Choke Vacuum Break

• Choke Unloader

Holley 4160 and 4150
(Except End
Inlet)

• Float

• Air Vent Valve

• Accelerator Pump

• Choke Vacuum Break

• Choke Unloader

Holley 2300 and 4150
(End
Inlet)

• Air Vent Valve (except 2300)

• Accelerator Pump

• Choke Vacuum Break

• Choke Unloader

Removal

Flooding, stumble on acceleration and other perform-

mance complaints are, in many instances, caused by the

presence of dirt, water, or other foreign matter in the

carburetor. To aid in diagnosing the cause of the com-

plaint, the carburetor should be carefully removed from

the engine without draining the fuel from the bowl.

The contents of the fuel bowl may then be examined for

contamination as the carburetor is disassembled.

1.
Remove air cleaner and gasket.

2.
Disconnect fuel and vacuum lines from carburetor.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL 6M-5

3.
Disconnect choke rod or choke cable.

4.
Disconnect accelerator linkage.

5.
If equipped with Automatic transmission, discon-

nect TV linkage.

6. Remove carburetor attaching nuts and/or bolts and

remove carburetor.

Test Before Installation -

It is good shop practice to fill the carburetor bowl

before installing the carburetor. This reduces the strain

on the starting motor and battery and reduces the pos-

sibility of backfiring while attempting to start the engine.

A fuel pump clamped to the bench, a small supply of fuel

and the necessary fittings enable the carburetor to be

filled1 and the operation of the float and'intake needle and

seat to be checked. Operate the throttle several times

and check the discharge from the pump jets before in-

stalling the carburetor.

Installation

1.
Be certain throttle body and intake manifold sealing

surfaces are clean.

2.
Install new carburetor to manifold flange gasket (if

required).

3.
Install carburetor over manifold studs.

4.
Start vacuum and fuel lines at carburetor.

5.
Install attaching nuts and/or bolts and tighten

securely.

6. Tighten fuel and vacuum lines.

7.
Connect and adjust accelerator and TV linkage.

8. Connect choke tube or choke rod.

9. Adjust idle speed and mixture, then install air

cleaner. #

Fuel Filter Maintenance

1.
Disconnect fuel line connection at inlet fuel filter

nut.

2.
Remove inlet fuel filter nut from carburetor with a

1"
box wrench or socket.

3.
Remove filter element and spring (fig. 4c).
Fig. 5C-Choke Coil-L6 Engine

4.

Fig. 4C-Fuel Filter
Check element for restriction by blowing on cone

end, element should allow air to pass freely.

5.
Clean element by washing in solvent and blowing out.

Blow in opposite direction of fuel flow.

NOTE: Element should be replaced if plugged

or if flooding ocpurs. A plugged filter will

result in a loss of engine power or rough (pul-

sating) engine feel, especially at high engine

speeds.

6. Install element spring, then install element in car-

buretor so small section of cone faces out.

7.
Install new gasket on inlet fitting nut then install

nut in carburetor and tighten securely.

8. Install fuel line and tighten connector.

Choke Coil Replacement

L6 Engines (Fig. 5c)

1.
Remove air cleaner then disconnect choke rod upper

clip.

2.
Remove bolts attaching choke coil to manifold, then

remove choke coil and choke rod as an assembly.

3.
Disconnect choke rod from choke coil.

4.
Connect choke rod to new choke coil and install as-

sembly on manifold.

5.
Install bolts and tighten securely.

6. Adjust and connect choke rod as outlined.

7.
Start and warm-up the engine then check operation

of choke and install air cleaner.

V8 Engines (Fig. 6c)

1.
Remove air cleaner then disconnect choke rod upper

clip.

2.
Remove choke coil as follows:

WITH ROCHESTER 2GV CARBURETOR

• Remove the choke coil shield by prying with a

screw driver in the cut out provided then re-

move the choke rod.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL 6M-6

Fig.
6C-Choke Coil-V8 Engine

• Remove bracket and choke coil assembly.

WITH ROCHESTER 4MV AND

HOLLEY CARBURETORS

• Remove the choke coil shield by prying with a

screw driver in the cut out provided then lift

shield carefully over rod.

• Remove choke rod, bracket screw and choke

coil assembly
3.
Install a new choke coil assembly being sure the

locating tab is in the forward hole of the intake

manifold then install mounting screw.

4.
Complete installation as follows:

WITH ROCHESTER 2GV CARBURETOR

• Check that the choke rod eye of the coil is

below the stop tab on the bracket then install

the choke
ro and adjust if necessary.

• Install the choke coil shield over the choke coil

and move shield to best fit along manifold.

WITH ROCHESTER 4MV AND

HOLLEY CARBURETORS

• Install the choke rod and adjust as necessary

(without choke coil shield installed).

• Disconnect choke rod upper end and lower choke

coil shield over choke rod and install over choke

coil.

• Move shield to best fit along manifold and con-

nect upper end of choke rod.

5. Be sure choke valve moves freely from full open

to full closed position.

6. Start and warm up the engine and check operation

of the choke.

7. Install the air cleaner.

Throttle Linkage Adjustment (Fig. 7c or 8c)

1.
Disconnect throttle rod swivel at throttle lever on

carburetor.

2.
On automatic transmission equipped vehicles dis-

connect TV rod at throttle lever.

3.
Hold carburetor throttle in wide open position, push

throttle rod rearward (to position accelerator pedal

at the floor mat) and adjust swivel to just enter hole

in throttle lever.

4.
Connect swivel to throttle lever and install accelera-

tor return spring.

CAMARO & CHEVY II V8

CHEVELLE & CHEVROLET

V8

CAMARO
&
CHEVY
II

V8

CHEVELLE &

CHEVROLET V8
ALL SERIES

IN LINE

ALL SERIES

INLINE

Fig.
7C—Throttle Linkage—Chevrolet, Chevelle, Chevy II and Camaro

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE FUEL 6M-7

5. On vehicles equipped with automatic transmission

hold throttle rod in full throttle position, pull TV

rod to full detent position and adjust TV rod to just

enter hole on throttle lever, then connect TV rod at

throttle lever.
NOTE:
If equipped with anti-stall device (dash-

pot),
set carburetor fast idle cam on high step

and adjust dash-pot to just contact throttle

lever.

327
CU.
IN.
427
CU.
IN.

Fig.
8C—Throttle Linkage-Corvette

AIR
CLEANERS

INDEX

Page

General Description 6M-7

Service Procedures . . 6M-8

Polyurethane. Element 6M-8

Maintenance 6M-8

Oil Bath 6M-8
Page

Maintenance
...........* 6M-8

Oil
Wetted
Paper
Element
6M-9

Replacement
* . 6M-9

Testing 6M-9

Tool J-7852 . 6M-9

GENERAL DESCRIPTION

Air cleaners on all models operate primarily to re-

move dust and dirt from the air that is taken into the

carburetor and engine. All air cleaners on engines

equipped with "Closed Positive" ventilation incorporate

flame arresters. Every 12,000 miles the flame ar-

resters should be removed, cleaned in solvent and blown

dry with compressed air.

An oil wetted polyurethane element air cleaner (fig. 1A)

is standard equipment on In Line engines. This type

cleaner element is reusable and should be removed,

cleaned, re-oiled and reinstalled every 12,000 miles or

more often during dusty or other adverse driving con-

ditions. The optional, oil bath air cleaner (available on
Chevrolets with L6 engine) should be cleaned and re-

filled with oil at oil change intervals.

On the V8 engines,, a replaceable, oil wetted paper

element type is used (fig; 2A). Both ends of me paper

element are bonded with plastisol sealing material.

The improved oil wetted paper elements have increased

filtering capacity over their dry paper predecessors.

Oil on the paper causes the element to become diBcolored

by a small amount of dirt but does not necessarily mean

the element is plugged or reduced in efficiency. Every

12,000 miles or more often during dusty or other adverse

driving conditions, either replace oil wetted paper ele-

ment or test element using ToolJ-7825.

CHEVROLET CHASSIS SOVICE/MANUAL

ENGINE FUEL 6M-8

^T^l^^/'-vN

COVER
BOTTOM

Fig. 1A—Polyurethane Element Air Cleaner
OIL RESISTANCE

SEAL

BOTTOM
BONDED PAPER

ELEMENT

COVER

Fig. 2A—Paper Element Air Cleaner

SERVICE
PROCEDURES

POLYURETHANE ELEMENT

Maintenance

1.
Remove cover wing nut, cover and filter element.

2.
Visibly check the element for tears or rips and re-

place if necessary.

3.
Clean all accumulated dirt and grime from air

cleaner bottom and cover. Discard air horn to air

cleaner gasket.

4.
/Remove support screen from element and wash

element in kerosene or mineral spirits; then squeeze

out excess solvent (fig. 3A).

NOTE: Never use a hot degreaser or any sol-

vent containing acetone or similar solvent*

5.
Dip element into light engine oil and squeeze out

excess oil.
NOTE: Never shake, swing or wring the ele-

me.nt to remove excess oil or solvent as this

may tear the polyurethane material. Instead,

"squeeze" the excess from the element.

6. Install element'on screen support (fig. 4A).

7.
Using a new gasket, replace air cleaner body over

carburetor air horn.

8. Replace the element in the air cleaner. Care must

be taken that the lower lip of the element is properly

placed in the assembly and that the filter material

is not folded or creased in any manner that would

cause an imperfect seal. Take the same precautions

when replacing the cover that the upper lip of the

element is in proper position.

9.<•
Replace cover and wing nut.

OIL BATH

Maintenance

L Remove air cleaner assembly.

2.
Remove cover and filter element assembly.

Empty oil out of

accumulated dirt.
cleaner and clean out all oil and

Fig. 3A—Cleaning Polyurethane Element

Fig.
4A—Polyurethane Support

CHEVROLET CHASSIS SERVICE MANUAL