A8L V8-4.2L (BFM) (2004)
Fuel Injector: Testing and Inspection
Injection Quantity, Checking For Proper Seal and Spray Pattern of Fuel Injectors
Injection Quantity, Checking For Proper Seal And Spray Pattern Of Fuel Injectors
Test requirement
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Fuel pressure OK.
Removing fuel rail pipe
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Remove engine compartment cover.
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Disconnect vacuum hose from fuel pressure regulator.
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Disconnect connector from fuel injectors, remove cable ties if necessary.
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Remove fuel rail from intake manifold and pull off from intake manifold with fuel injectors upward.
Check proper seal of fuel injectors
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Insert fuel injector to be tested in a measuring glass from VAG1602 injection quantity test device.
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Connect VAG1598/31 test box at wiring harness to Engine Control Module (ECM), do not connect ECM See: Computers and Control
Systems/Testing and Inspection/Reading and Clearing Diagnostic Trouble Codes/Scan Tool Connecting
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Bridge terminals 1 and 65 at test box using adapter cables from V.A.G 1594 A connector test kit (this step supplies Ground -GND- to one side of
relay coil of Fuel Pump -FP- relay).
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Switch ignition on.
NOTE: After switching ignition on, Fuel Pump (FP) will run continuously, even with engine not running. This is true because: Fuel Pump (FP)
relay is supplied with B+ via central electronics after ignition is switched on. Fuel Pump (FP) relay receives Ground (GND) via the cable bridge in
test box.
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Check proper seal of fuel injectors (visual inspection). With Fuel Pump (FP) running, only 1 to 2 drops per minute may drip out per injector.
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If fuel loss is greater, stop Fuel Pump (FP) from running (switch ignition off) and replace faulty fuel injector.
Checking injection quantity
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Insert fuel injector to be tested in a measuring glass from VAG1602 injection quantity test device.
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Connect one terminal of fuel injector to engine Ground (GND) using an adapter cable and an alligator clip from VAG1594A connector test kit.
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Connect the second terminal of fuel injector to B+ using VAG1348/3A remote control, VAG1348/3-2 adapter cable and assisting cable.
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Bridge terminals 1 and 65 at test box using wires from VAG1594A adapter test kit.
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Switch ignition on.
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Fuel Pump (FP) must run.