Fuel Injectors For Injection Quantity and Proper Seal, Checking
Checking injection quantity and proper seal of fuel injectors
Recommended special tools and equipment
- VAG1348/3A remote control with VAG1348/3-2 adapter cable
- V.A.G 1602 tester for quantity of injected fuel
Without illustration:
- VAG1594A connector test kit
Test requirement
- Fuel pressure must be OK, fuel pressure regulator and retaining pressure, checking. Testing and Inspection
WARNING: Fuel system is under pressure! Before opening system, place rags around the connection point. Then release pressure by carefully loosening connection.
Test sequence
- Remove intake air hose between Mass Air Flow (MAF) sensor and throttle valve control module, item 1 .
- Remove upper part of intake manifold (with both intake manifold side parts), item 8 .
NOTE:
- When removing the upper part of the intake manifold, ensure that the alignment pins are positioned in lower part of the intake manifold and do not fall into the intake channels!
- Seal the intake channels in lower part of intake manifold using a clean rag.
- 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
- Remove mounting bolts from fuel distributor.
- Lift fuel distributor with fuel injectors off lower part of intake manifold and support it.
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test
- Bridge test box sockets 1 and 65 using adapter cables.
NOTE: The only purpose of this step is to allow the Fuel Pump (FP) to run with the engine at standstill.
- Switch ignition on.
Checking proper seal
- Check proper seal of fuel injectors (visual inspection). With Fuel Pump (FP) running, only 1 to 2 drops per minute should escape from each valve.
If fuel loss is greater:
- Switch ignition off.
- 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-), item 9 .
Installation of fuel injectors is the same in reverse order. Note the following:
- O-rings on all fuel injectors must be replaced and coated lightly 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 on intake manifold 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. Monitors, Trips, Drive Cycles and Readiness Codes
Checking Injection Quantity
Test requirement
- Test box still connected and test box sockets 1 and 65 bridged with adapter cables.
Test sequence
- Insert a fuel injector to be tested into a measuring tube of VAG1602 tester for fuel injection quantity.
- Using adapter cables, connect one terminal of fuel injector to be checked to engine Ground (GND).
- Use adapter cable to connect second terminal of fuel injector to VAG1348/3 remote control with VAG1348/3-2 adapter cable.
- Connect alligator clip to B+.
- 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 injector
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-), item 9 .
Installation of fuel injectors is the same in reverse order. Note the following:
- O-rings on all fuel injectors must be replaced and coated lightly 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 on intake manifold 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. Monitors, Trips, Drive Cycles and Readiness Codes