Fiat Bravo Quiz
Diesel injection system

Removing and installing injection nozzles

In this manual: Diesel injection system
Dear Reader — 1Engine — 35Engine lubrication — 3Engine cooling — 10Ignition/spark plugs — 14Fuel system — 10Petrol fuel injection — 13Diesel injection system — 13Exhaust system — 7Clutch — 7Transmission / Gearshift / Automatic Transmission — 5Front Axle — 11Rear axle — 4Steering — 9Wheel alignment — 1Brake system — 22Wheels and tyres — 10Body — 34Heating — 6Electrical system — 39Lighting system — 14Instruments — 7Windscreen wiper system — 8Vehicle care / tools — 6Jump Starting / Towing the Vehicle — 3Jacking up the vehicle — 1Fiat Bravo / Brava Maintenance Schedule — 1Maintenance — 38Wiring diagrams — 5
6steps
~36min
2/5difficulty
03060901201507052N·mlb·ft
Tightening torque found on this page
Done 0 of 6
55/74 kW engine (75/100 hp) up to 9/98

Faulty injection nozzles can cause heavy engine knocking and suggest bearing damage. For such complaints, run the engine at idle and loosen the injection line union nuts one after another.

If the knocking disappears after loosening a union nut, this indicates a faulty nozzle.

Faulty nozzles can also be located by loosening the injection line union nuts one after another while the engine runs at fast idle. If the engine speed remains constant after loosening a union nut, this indicates a faulty nozzle. The nozzle can be checked with a pressure gauge (workshop work).

The first signs of nozzle faults appear as follows.

  • Misfiring

  • Knocking in one or more cylinders

  • Engine overheats

  • Loss of engine power

  • Excessive black exhaust smoke

  • High fuel consumption

Removal

  • Carefully clean the injection lines from the outside with cold cleaner or diesel fuel.

Einspritzdüsen aus-und einbauen

  • Remove the injection lines completely: loosen the union nuts at the pump and injection nozzles with an open-end wrench, for example Hazet 4550. Caution: do not change the bend shape of the lines.

Einspritzdüsen aus-und einbauen

  • Remove the injection nozzles with a socket insert, 27 mm A/F.

    An extended socket, for example Hazet 4555-1, is required for this. (Lower 4 arrows = glow plugs.)

Warning: the injection nozzle of cylinder 1 (timing belt side) has an electrical connection (needle movement sensor).

Disconnect the supply line and unscrew the injection nozzle with a socket. If necessary, first prepare the socket with a slot for the cable. Route the cable through the socket.

  • Each injection nozzle has a heat shield to protect it from heat damage. Remove the heat shields from the bores in the cylinder head.

Warning: always use new heat shields when refitting the injection nozzles.

  • Clamp the nozzle holder between soft-metal jaws in a vise. Disassemble the injection nozzle.

  • Check the nozzle needle seat for dents or roughness, and check the nozzle needles for wear or damage.

    Clean carbon from the spray nozzle with a wooden spatula. The needle must slide into the nozzle under its own weight alone.

Warning: never machine the nozzle or nozzle needle with wire, file or emery cloth. Do not mix up the individual nozzle parts. The workshop can regulate the nozzle spray pressure by fitting shims of different thickness.

  • Screw the upper and lower nozzle parts together to 70 N·m.

Einspritzdüsen aus-und einbauen

  1. Fuel return

  2. Compression spring

  3. Nozzle body

  4. Base

  5. Nozzle needle

  6. Needle tip

Installation
Einspritzdüsen aus-und einbauen

  • Always use new heat shields between the cylinder head and the injection nozzle. The recess must point upwards, the arrow points towards the cylinder head.

  • Tighten the injection nozzles to 55 N·m.

  • Fit the injection lines and tighten the union nuts to 25 N·m.

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