Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 1248

6E1–68

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Injector Coil Test Procedure (Steps 1–6) 

And Injector Balance Test Procedure (Steps 7–11)

R262001

CYLINDER

1

2

3

4

1st Reading

296 kPa

(43psi)

296 kPa

(43psi)

296 kPa

(43psi)

296 kPa

(43psi)

2nd Reading

131 kPa

(19 psi)

117 kPa

(17 psi)

124 kPa

(18 psi)

145 kPa

(21 psi)

Amount of Drop (1st Reading–2nd
Reading

165 kPa

(24 psi)

179 kPa

(26 psi)

172 kPa

(25 psi)

151 kPa

(22 psi)

Av. drop = 166 kPa/24 psi  +/–10
kPa/1.5 psi = 156 – 176 kPa or  22.5
– 25.5 psi

OK

Faulty, Rich
(Too Much Fuel
Drop)

OK

Faulty, Lean
(Too Little Fuel
Drop)

NOTE: These figures are examples only.

6E1–69

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Injector Coil Test Procedure (Steps 1–6) 

And Injector Balance Test Procedure (Steps 7–11)

 

Step

Action

Value(s)

Yes

No

1

Was the ”On–Board Diagnostic (OBD) System Check”
performed?

—

Go to 

Step 2 

Go to 

OBD

System

Check 

2

1. Turn the engine OFF.

NOTE: In order to prevent flooding of a single cylinder
and possible engine damage, relieve the fuel pressure
before performing the fuel injector coil test procedure.

2. Relieve the fuel pressure. Refer to Test Description

Number 2. 

3. Connect the J 39021–5V Fuel Injector Tester to B+

and ground, and to the J39021–90 Injector Switch
Box.

4. Connect the injector switch box to the grey fuel

injector harness connector located at the front of the
EVAP canister bracket.

5. Set the amperage supply selector switch on the fuel

injector tester to the ”Coil Test” 0.5 amp position.

6. Connect the leads from the J 39200 Digital

Voltmeter (DVM) to the fuel injector tester. Refer  to
the illustrations associated with the test description.

7. Set the DVM to the tenths scale (0.0).
8. Observe the engine coolant temperature.

Is the engine coolant temperature within the specified
values?

10

°

C (50

°

F)

to 35

°

C

(95

°

F)

Go to 

Step 3 

Go to 

Step 5 

3

1. Set the injector switch box to injector #1.
2. Press the ”Push to Start Test” button on the fuel

injector tester.

3. Observe the voltage reading on the DVM.

IMPORTANT: The voltage reading may rise during the
test.

4. Record the lowest voltage observed after the first

second of the test.

5. Set the injector switch box to the next injector and

repeat steps 2, 3, and 4.

Did any fuel injector have an erratic voltage reading
(large fluctuations in voltage that did not stabilize) or a
voltage reading outside of the specified values?

5.7–6.6 V

Go to 

Step 4 

Go to 

Step 7 

4

Replace the faulty fuel injector(s). Refer to Fuel
Injector.

Is the action complete?

—

Go to 

Step 7 

—

6E1–70

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Injector Coil Test Procedure (Steps 1–6) 

And Injector Balance Test Procedure (Steps 7–11)

  (Cont'd)

Step

No

Yes

Value(s)

Action

5

1. Set the injector switch box to injector #1.
2. Press the ”Push to Start Test” button on the fuel

injector tester.

3. Observe the voltage reading on the DVM.

IMPORTANT: The voltage reading may rise during the
test.

4. Record the lowest voltage observed after the first

second of the test.

5. Set the injector switch box to the next injector and

repeat steps 2, 3, and 4.

Did any fuel injector have an erratic voltage reading
(large fluctuations in voltage that did not stabilize) or a
voltage reading above the specified value?

9.5 V

Go to 

Step 4 

Go to 

Step 6 

6

1. Identify the highest voltage reading recorded  (other

than those above 9.5 V).

2. Subtract the voltage reading of each injector from

the highest voltage selected in step 1. Repeat until
you have a subtracted value for each injector.

For any injector, is the subtracted value in step 2
greater than the specified value?

0.6 V

Go to 

Step 4 

Go to 

Step 7 

7

CAUTION:  In order to reduce the risk of fire and
personal injury, wrap a shop towel around the
fuel pressure connection. The towel will absorb
any fuel leakage that occurs during the
connection of the fuel pressure gauge. Place the
towel in an approved container when the
connection of the fuel pressure gauge is
complete.

1. Connect the J 34730–1 Fuel Pressure Gauge to the

fuel pressure test port.

2. Energize the fuel pump using the Tech 2.
3. Place the bleed hose of the fuel pressure gauge into

an approved gasoline container.

4. Bleed the air out of the fuel pressure gauge.
5. With the fuel pump running, observe the reading on

the fuel pressure gauge.

Is the fuel pressure within the specified values?

296 kPa– 376

kPa (43–55

psi)

Go to 

Step 8 

Go to  

Fuel

System

Diagnosis 

8

Turn the fuel pump OFF.

Does the fuel pressure remain constant?

—

Go to 

Step 9 

Go to  

Fuel

System

Diagnosis 

6E1–71

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Injector Coil Test Procedure (Steps 1–6) 

And Injector Balance Test Procedure (Steps 7–11)

  (Cont'd)

Step

No

Yes

Value(s)

Action

9

1. Connect the J 39021–5V Fuel Injector Tester and

J39021–90 Injector Switch Box to the fuel injector
harness connector.

2. Set the amperage supply selector switch on the fuel

injector tester to the ”Balance Test” 0.5–2.5 amp
position.

3. Using the Tech 2 turn the fuel pump ON then OFF in

order to pressurize the fuel system.

4. Record the fuel pressure indicated by the fuel

pressure gauge after the fuel pressure stabilizes.
This is the first pressure reading.

5. Energize the fuel injector by depressing the Push to

Start Test button on the fuel injector tester.

6. Record the fuel pressure indicated by the fuel

pressure gauge after the fuel pressure gauge
needle has stopped moving. This is the second
pressure reading.

7. Repeat steps 1 through 6 for each fuel injector.
8. Subtract the second pressure reading from the first

pressure reading for one fuel injector. The result is
the pressure drop value.

9. Obtain a pressure drop value for each fuel injector.
10.Add all of the individual pressure drop values. This

is the total pressure drop.

11. Divide the total pressure drop by the number of fuel

injectors. This is the average pressure drop.

Does any fuel injector have a pressure drop value that
is either higher than the average pressure drop or lower
than the average pressure drop by the specified value?

10 kPa (1.5

psi)

Go to 

Step 10

Go to 

OBD

System

Check 

10

Re–test any fuel injector that does not meet the
specification. Refer to the procedure in step 11.

NOTE: Do not repeat any portion of this test before
running the engine in order to prevent the engine from
flooding.

Does any fuel injector still have a pressure drop value
that is either higher than the average pressure drop or
lower than the average pressure drop by the specified
value?

10 kPa (1.5

psi)

Go to 

Step 11

Go to

Symptoms 

11

Replace the faulty fuel injector(s). Refer to Fuel
Injector.

Is the action complete?

—

Verify repair

—