Chevrolet CHEVY VAN G10 SERIES Service Manual page 190

ENGINE FUEL 6M-16
INSPECTION
The fuel pum p (Fig. 3P) should be checked to m ake sure
the m ounting bolts an d inlet and o u tlet connections are tight.
TEST
Always test pum p while it is m o unted on the engine and be
sure there is gasoline in the tank.
The line from the tan k to the p um p is th e suction side o f
the system and the line from the pum p to the carburetor is the
pressure side o f the system . A leak on the pressure side,
therefore, w ould be m ade apparent by dripping fuel, b u t a leak
on the suction w ould n o t be ap p arent except for its effect o f
reducing volum e o f fuel on th e pressure side.
1. T ighten any loose line connections and look for bends or
kinks in lines.
2. D isconnect fuel pipe at carburetor. D isconnect dis­
trib u to r to coil prim ary wire so th a t engine can be
cranked w ith o u t firing. Place suitable container at end of
pipe and crank engine a few revolutions. If little or no
gasoline flows from o pen end o f pipe then fuel pipe is
clogged or pu m p is inoperative. Before removing pum p
disconnect fuel pipe at gas ta n k and o u tlet pipe and blow
th ro u gh them w ith an air hose to m ake sure they are
clear. R econnect pipes and retest while cranking engine.
C A U T I O N : Whenever
rem otely at the starter, w ith a special jum per cable
or other means the distributor primary lead must be
disconnected fro m the negative post on the coil and
the ignition switch must be in the " O N " position.
Failure to do this w ill result in a damaged grounding
circuit in the ignition switch.
SERVICE PROCEDURES
the engine is cranked
3. If fuel flows from pum p in good volum e from pipe at
carb ureto r, check fuel delivery pressure to be certain th at
pum p is operating w ithin specified limits as follows:
a. A ttach a fuel p um p pressure test gauge to dis­
connect end o f pipe.
b. R un engine at approxim ately 4 5 0 —1,000 rpm (on
gasoline in carburetor bow l) and note reading on
pressure gauge.
c. If pum p is operating properly th e pressure will be
w ithin specifications and will rem ain co nstan t at
speeds betw een 4 5 0 —1,000 rpm . If pressure is too
low , to o high, or varies significantly at different
speeds, the pum p should be replaced.
REMOVAL
N O T E : Whenever disconnecting
F u e l P u m p O u t l e t
double-wrench to avoid damaging fuel pump.
1. D isconnect fuel inlet and ou tlet pipes at fuel pum p.
2. Remove fuel pum p m ounting bolts and remove pum p
and gasket.
8
3. On V engines if push ro d is to be rem oved, remove pipe
plug and push rod (4 02 cu. in. engines), and fuel pum p
adapter and gasket and push ro d (307, 350 and 400 cu.
in. engines).
IN S TA LLA TIO N
8
1. On V engines, if fuel pum p push rod has been rem oved,
install push rod and pipe fittin g or fuel pum p adapter
using gasket sealer on gasket or pipe fitting.
2. Install fuel pum p using a new gasket and tighten securely.
Use sealer on fuel pum p m ounting bolt threads.
N O T E : On V 8 engines, a pair of mechanical fingers
or heavy grease may be used to hold fuel pump push
rod up w hile installing fuel pump (Fig. 4P).
3. C onnect fuel pipes to pum p.
4. S tart engine and check for leaks.
Fig. 4P —Installing V -8 Engine Fuel Pump
or connecting
P ip e F i t t i n g , a lw a y s
C H E V Y V A N S H O P M A N U A L