Removing and installing injectors (intake manifold): VW (CHHB, CXDA)
Step-by-step removing and installing injectors (intake manifold) for the VW (CHHB/CXDA): 13 steps. What to remove, in what order, and what to check after.
Removing and refitting the injectors that sit in the intake manifold on the CHHB and CXDA engines, platform codes listed below. The injectors come out together with the fuel rail, so the job begins at the rail: the fuel supply hose is disconnected from the manifold, the connectors are pulled from their retainer and unplugged, the rail wiring harness is freed and laid aside, and the rail bolts are removed. The rail and injectors are then pulled straight upwards and the individual injector connectors released. New O-rings are fitted every time, lightly wetted with clean engine oil, and the injectors pushed by hand into a manifold bore that is free of oil and grease. Even seating by hand is what prevents a leak.
🧭 Before you start
Disconnect the supply hose, unplug and free the connectors and rail harness, unbolt the fuel rail and pull it upwards with the injectors. Disconnect the injectors, renew their O-rings and lightly oil them. Reconnect, press the rail and injectors by hand into the clean manifold bores to the stop, fit the rail and reverse the remaining steps.
Fits: platform codes AU1, BX5
- Renewed: injector o-rings
Don't miss
- Renew all injector O-rings; old ones harden and leak.
- Moisten the O-rings with clean engine oil only, not grease or silicone.
- Manifold bores must be free of oil and grease before the injectors go in.
- Push the rail home by hand evenly; do not draw it down with the bolts.
- Check for fuel leaks at the rail and supply hose with the pump primed, as general practice.
Written for this job from the workshop steps below · TorqFix editorial.
📋 Procedure
- Disconnect fuel supply hose (1) from intake manifold.
- Pull electrical connectors (3) out of retainer.
- Disconnect electrical connectors (4 and 5).
- Free fuel rail wiring harness (1) from fittings and lay it to one side.
- Unscrew bolts (arrows) from fuel rail.
- Carefully pull fuel rail with injectors upwards to remove.
- Disconnect connectors from injectors.
- Renew injector O-rings.
- Before installing O-rings, lightly moisten them with clean engine oil.
- Connect injector connectors.
- Push fuel rail with injectors by hand as far as stop into hole in intake manifold (which must be free of oil and grease).
- The remaining installation steps are carried out in the reverse sequence.
- Install fuel rail.
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Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com
The story behind TorqFix →Workshop data on this page last updated 20 Sep 2026.