Fuel Injectors, Checking

Special tools and workshop equipment required

Torque wrench (5 to 50 Nm) VAG 1331

Fig 1: Identifying Torque Wrench (5 To 50 Nm) V.A.G 1331
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
Multimeter VAG 1526 or Multimeter VAG 1715
Voltage test lamp VAG 1527
Connector test kit VAG 1594
Wiring diagram

Test requirements

The corresponding fuses of fuel injectors -N30- to -N33-, -N83-, -N84-) in E-box (in plenum chamber, left side) must be OK: Refer to appropriate SYSTEMS WIRING DIAGRAM

Fig 2: Identifying Fuses In E-Box (Plenum Chamber, Left)
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Motronic Engine Control Module (ECM) Power Supply Relay -J271- must be OK, check: appropriate SYSTEMS WIRING DIAGRAM
Battery voltage must be at least 11.5 volts.
Ground (GND) connections between engine and chassis must be OK.
All electrical consumers such as, lights and rear window defroster must be switched off.
If vehicle is equipped with an A/C system, it must be switched off.
Parking brake must be engaged or else daylight driving lights will be switched on.
For vehicles with automatic transmission, selector lever must be in P.
Engine speed (RPM) sensor must be OK, checking.
Ignition switched off.

Test sequence

-- Remove intake manifold change-over, Intake manifold change-over, disassembling and assembling.

-- Disconnect harness connectors for Fuel Injectors 1 through 6 (N30 -- to -N33-, -N83-, -N84-).

Fig 3: Disconnecting Harness Connectors For Fuel Injectors 1 Through 6

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Resistance values of fuel injectors, checking

-- Test resistance of fuel injectors between terminals.

Specified value: 13.0 to 16.0 Ω

If specified value is not obtained:

-- Replace faulty fuel injector (Cylinder 1 Fuel Injector -N30- to Cylinder 4 Fuel Injector -N33-, Cylinder 5 Fuel Injector -N83- to Cylinder 6 Fuel Injector -N84-).

Note the following when installing the fuel injectors:

Replace O-rings on all fuel injectors and wet them slightly with clean motor oil.
Insert fuel injectors into fuel distributor perpendicular and in the right position, and secure them with retaining clips.
Position fuel distributor with secured fuel injectors and apply uniform pressure to press it in.
The connectors must audibly engage on valves when attached.

-- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.

-- Generate readiness code.

Checking voltage supply

-- Connect diode test lamp to fuel injector connector to be tested, terminal 1 + Ground (GND).

Fig 4: Checking Voltage Between Fuel Injector Connector Terminal 1 And Ground

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-- Operate starter and test voltage supply for fuel injector.

LED must light up.

-- Switch ignition off.

If LED does not light up:

-- Check voltage supply at 2-pin connector terminal 1 to Motronic Engine Control Module (ECM) Power Supply Relay -J271- according to wiring diagram: Refer to appropriate SYSTEMS WIRING DIAGRAM

-- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.

-- Generate readiness code.

Activation and voltage supply, checking

-- Connect diode test lamp to the connector terminals 1 + 2 of the fuel injector to be checked.

Fig 5: Activation And Voltage Supply, Checking

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-- Operate starter and test activation of fuel injector.

LED should flicker.

-- Switch ignition off.

If LED does not flicker:

-- Check wires according to wiring diagram.

Checking wiring

-- Connect test box to control module wiring harness, connect test box for wiring test.

-- Check wires between test box and 2-pin connector for open circuit according to wiring diagram.

Fig 6: 2-Pin Connector & Terminals

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Wire resistance: max. 1.5 Ω

Component	Connector	Test box
Cylinder 1 Fuel Injector -N30-	Terminal 2	Socket 96
Cylinder 2 Fuel Injector -N31-	Terminal 2	Socket 112
Cylinder 3 Fuel Injector -N32-	Terminal 2	Socket 88
Cylinder 4 Fuel Injector -N33-	Terminal 2	Socket 113
Cylinder 5 Fuel Injector -N83-	Terminal 2	Socket 97
Cylinder 6 Fuel Injector -N84-	Terminal 2	Socket 89

-- Check wires for short circuit to B+ or Ground (GND).

Specified value: ∞ Ω

If there is no malfunction in wire connection:

-- Replace Motronic Engine Control Module (ECM) -J220-.

Injection quantity and proper seal of fuel injectors, checking

Fig 7: Identifying Special Tools -- Fuel Injectors, Checking Injection Quantity And Seal

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Special tools and workshop equipment required

Torque wrench (5 to 50 Nm) VAG 1331
Remote control VAG 1348/3A with adapter cables VAG 1348/3-2 and VAG 1348/3-3
Connector test kit VAG 1594A
Tester for quantity of injected fuel VAG 1602

Test requirements

Fuel pressure must be OK, check, fuel pressure regulator and retaining pressure, checking.
Ignition switched off.

Test sequence

Observe safety precautions.

Observe rules for cleanliness.

-- Remove intake manifold change-over, Intake manifold change-over, disassembling and assembling.

NOTE:

Seal the intake channels in intake manifold change-over and in cylinder head using a clean rag.

-- Remove fuel rail completely along with the fuel injectors (fuel supply line remains connected), fuel rail with fuel injectors, disassembling and assembling.

Check for proper seal.
Check injection quantity.

Checking Proper Seal

-- Remove relays for electric Fuel Pump (FP) from relay carrier:

Fig 8: Identifying Fuel Pump (FP) 2 Relay -J49- & Fuel Pump (FP) Relay -J17-

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Fuel Pump (FP) 2 Relay -J49-, (Fuel Pump -FP-, right), position C19
Fuel Pump (FP) Relay -J17-, (Fuel Pump -FP-, left), position A6.

NOTE:

Do not use metallic tools to pry off relays from relay carrier. The terminals could conduct electricity.

-- Now connect adapter VAG 1348/3-3 of remote control to connector of Fuel Pump (FP) Relay for left and right Fuel Pumps (FP):

Connector (arrow) of Fuel Pump (FP) Relay for right Fuel Pump (FP).

Fig 9: Connecting V.A.G 1348/3A Remote Control To Connector Of Fuel Pump (FP) Relay For Right Fuel Pump (FP) Using V.A.G 1348/3-3 Adapter
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Connector (arrow) of Fuel Pump (FP) Relay for left Fuel Pump (FP).

Fig 10: Checking Delivery Quantity Of Left Pump
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-- Connect remote control alligator clip to plus pole in engine compartment.

-- Operate remote control:

Fuel Pumps (FP) must run.

-- Check proper seal of fuel injectors (visual inspection). With Fuel Pumps (FP) running, only 1 to 2 drops per minute should escape from each valve.

If fuel loss is greater:

-- Replace faulty fuel injector (Cylinder 1 Fuel Injector -N30- to Cylinder 4 Fuel Injector -N33-, Cylinder 5 Fuel Injector -N83- to Cylinder 6 Fuel Injector -N84-).

Note the following when installing fuel injectors:

Replace O-rings on all fuel injectors and wet them slightly with clean motor oil.
Insert fuel injectors into fuel distributor perpendicular and in the right position, and secure them with retaining clips.
Position fuel distributor with secured fuel injectors and apply uniform pressure to press it in.
The connectors must audibly engage on valves when attached.

-- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.

-- Generate readiness code.

Checking injection quantity

Fuel Pump (FP) relays for Fuel Pumps (FP), left and right, are located at their positions:

Fig 11: Identifying Fuel Pump (FP) 2 Relay -J49- & Fuel Pump (FP) Relay -J17-
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Fuel Pump (FP) 2 Relay -J49-, (Fuel Pump -FP-, right), position C19
Fuel Pump (FP) Relay -J17-, (Fuel Pump -FP-, left), position A6.

Test sequence

-- Connect test box to control module wiring harness, connect test box for wiring test.

-- Bridge test box sockets 1 and 65 using adapter cables.

NOTE:

The purpose of this work step is to allow the Fuel Pump (FP), left, to run with the engine at standstill.

-- Insert a fuel injector to be tested into a measuring tube of tester for fuel injection quantity VAG 1602.

-- Using adapter cables, connect one fuel injector terminal to be checked to engine Ground (GND).

Fig 12: Connecting Second Fuel Injector Terminal With Adapter Cable To Remote Control (V.A.G. 1348/3A With Adapter Cable V.A.G 1348/3-2)

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-- Use adapter cable to connect second terminal of fuel injector to remote control VAG 1348/3 with VAG 1348/3-2 adapter cable.

-- Connect remote control alligator clip to plus pole in engine compartment.

-- Operate remote control for 30 seconds.

-- Repeat test on other fuel injectors. Use new graduated measuring glasses for this.

-- After all fuel injectors have been activated, place graduated measuring glasses on a level surface and compare quantity of injected fuel. Specified value: 128 to 140 ml per valve

If the measured value of one or more fuel injectors is below or above the indicated specified value:

-- Replace faulty fuel injector (Cylinder 1 Fuel Injector -N30- to Cylinder 4 Fuel Injector -N33-, Cylinder 5 Fuel Injector -N83- to Cylinder 6 Fuel Injector -N84-).

Note the following when installing fuel injectors:

Replace O-rings on all fuel injectors and wet them slightly with clean motor oil.
Insert fuel injectors into fuel distributor perpendicular and in the right position, and secure them with retaining clips.
Position fuel distributor with secured fuel injectors and apply uniform pressure to press it in.
The connectors must audibly engage on valves when attached.

Final Procedures

After the repair work, the following work steps must be performed in the following sequence:

Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .