Fuel Injectors, Checking

Special tools and workshop equipment required

Multimeter VAG1526 or multimeter VAG1715
Voltage test lamp VAG1527
Connector test kit VAG1594
Wiring diagram

Test requirements

Respective fuses of fuel injectors (Cylinder 1 Fuel Injector -N30- to Cylinder 4 Fuel Injector -N33-, Cylinder 5 Fuel Injector -N83- to Cylinder 8 Fuel Injector -N86-) in fuse box (instrument panel, left) must be OK: Refer to SYSTEM WIRING DIAGRAM

Fig 1: Identifying Fuse Box (Instrument Panel, Left)
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
Fuses in E-box (in plenum chamber, left) must be OK: Refer to SYSTEM WIRING DIAGRAM

Fig 2: Identifying Fuses In E-Box (In Plenum Chamber, Left)
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
Motronic Engine Control Module (ECM) Power Supply Relay -J271- must be OK, check: Refer to SYSTEM 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, for example, 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 position.
Engine speed (RPM) sensor must be OK, checking ENGINE SPEED SENSOR, CHECKING .
Ignition switched off.

Test sequence

-- Disconnect harness connector of fuel injectors (Cylinder 1 Fuel Injector -N30- to Cylinder 4 Fuel Injector -N33-, Cylinder 5 Fuel Injector -N83- - to Cylinder 8 Fuel Injector -N86-), cylinder bank 1 and 2.

NOTE:

Bank 1 = Cylinder bank 1, in direction of travel, right.

Bank 2 = Cylinder bank 2, in direction of travel, left.

Resistance values of fuel injectors, checking

-- Test resistance of fuel injectors between terminals.

Specified value: 13.0...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 8 Fuel Injector -N86-).

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 on intake manifold using 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 connector of fuel injector to be tested, terminal 1 + Ground (GND).

Fig 3: 2-Pin Electrical Harness Connector & Terminals

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- 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 SYSTEM 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 + 2of the fuel injector to be checked.

Fig 4: 2-Pin Electrical Harness Connector & Terminals

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- 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 5: 2-Pin Electrical Harness Connector & Terminals

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

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	Socket19
Cylinder 3 Fuel Injector -N32-	Terminal 2	Socket 113
Cylinder 4 Fuel Injector -N33-	Terminal 2	Socket88
Cylinder 5 Fuel Injector -N83-	Terminal 2	Socket 97
Cylinder 6 Fuel Injector -N84-	Terminal 2	Socket 112
Cylinder 7 Fuel Injector -N85-	Terminal 2	Socket24
Cylinder 8 Fuel Injector -N86-	Terminal 2	Socket89

-- Also 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- ENGINE CONTROL MODULE, REPLACING .

Injection quantity and proper seal of fuel injectors, checking

Fig 6: Identifying Special Tools - Checking Injectors For Leaks And Quantity Injected

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Special tools and workshop equipment required

Remote control VAG1348/3A with adapter cable VAG1348/3-2
Tester for quantity of injected fuel VAG1602

Without illustration:

Connector test kit VAG1594A

Test requirements

Fuel pressure must be OK, check FUEL PRESSURE REGULATOR AND RESIDUAL PRESSURE, CHECKING , fuel pressure regulator and retaining pressure, checking.
Ignition switched off.

Test sequence

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

Checking for proper seal.
Check injection quantity.

Checking for proper seal

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

Fig 7: Identifying Fuel Pump Relays

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Fuel Pump (FP) Relay -J17-, (Fuel Pump -FP-, right), position C20
Fuel Pump (FP) 2 Relay -J49-, (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 VAG1348/3-3 of remote control to connector of Fuel Pumps (FP) Relay, left and right:

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

Fig 8: 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
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
Connector (arrow) of Fuel Pump (FP) Relay for left Fuel Pump (FP).

Fig 9: Checking Delivery Quantity Of Left Pump
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Connect alligator of remote control to B+ connection -1-.

Fig 10: Connecting Alligator Of Remote Control To B+ Connection

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Operate the remote control:

Fuel Pumps (FP) must be running.

-- Check proper seal of fuel injectors (visual inspection). With Fuel Pumps (FP) running, only 1 to 2 drops per minute must 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 8 Fuel Injector -N86-).

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 on intake manifold using 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 Relays
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Fuel Pump (FP) Relay -J17-, (Fuel Pump -FP-, right), position C20
Fuel Pump (FP) 2 Relay -J49-, (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 only purpose of this work step is to allow the Fuel Pump (FP), right, to run with the engine at standstill.

-- Insert a fuel injector to be tested into a measuring tube of tester for fuel injection quantity VAG1602.

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

Fig 12: Checking Fuel Injector

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Use adapter cable to connect second terminal of fuel injector to remote control VAG1348/3 with adapter cable VAG1348/3-2.

-- Connect alligator of remote control to B+ connection -1-.

Fig 13: Connecting Alligator Of Remote Control To B+ Connection

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Switch ignition on.

-- Operate remote control for 30 seconds.

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

-- Switch ignition off.

-- After all fuel injectors have been activated, place graduated measuring glasses on a level surface and compare quantity of injected fuel.

Specified value: 95 to 115 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 8 Fuel Injector -N86-).

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 on intake manifold using 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.