Pontiac Fiero 1988 Service Manual page 682

DRIVEABILITY AND EMISSIONS - FUEL INJECTION (PORT) 6E3-C2-17
MOTE: If injectors are suspected of being dirty, they should be
cleaned using an approved tool and procedure prior to
performing this test. The fuel
pressure
test in Section A
r
Chart A-7, should be completed prior to this test.
CHART C-2A
INJECTOR BALANCE TEST
2 . 8 L "P" SERIES (PORT)
Step 1. If engine is at operating temperature, allow a 10 minute "cool d o w n " period then connect
fuel pressure gauge and injector tester.
1. ignition "OFF".
2. Connect fuel pressure gauge and injector tester.
3 . Ignition
"OH",
4. Bleed off air in gauge. Repeat until all air is bled from gauge.
Step 2. Run test:
1 . Ignition "OFF" for 10 seconds.
2. Ignition "ON". Record gauge pressure. (Pressure must hold steady, if not see the Fuel
System diagnosis. Chart A-7, in Section A ) .
3.
Turn injector on, by depressing button on injector tester, and note pressure at the
instant the gauge needle stops.
Step 3.
1. Repeat step 2 on all injectors and record pressure drop on each.
Retest injectors that appear faulty (Any injectors that have a 10 kPa difference, either
more or less, in pressure from the average). If no problem is found, review Symptoms
Section B.
— EXAMPLE —
CYLINDER 1 2
3
4
5
6
1ST READING 225 225
225
225
225
225
2ND READING 100 100 100 90
100 115
AMOUNT OF DROP
125 125 125
135 125
110 j
O K
OK OK
FAULTY, RICH
( T O O MUCH)
(FUEL DROP)
O K
FAULTY, LEAN
(TOO LITTLE)
(FUEL DROP)
6-13-86 * 5 S 1671-6E