Caterpillar — Fuel Injection Nozzles - Test/Exchange
Testing & diagnosis
From a Caterpillar owner's manual covering: C3.3, C3.3 Rental Generator Set, C4.4, C4.4 Rental Generator Set, D4D1-Up, GLE1-Up, N3X1-UP, N4R1-Up, N4X1-Up, X3B1-UP, XYC1-Up, XYD1-Up. Check it applies to your exact model before use.
Applies to: Caterpillar C3.3, Caterpillar C4.4
Before you start
- Fuel leaked onto hot surfaces or electrical components can cause a fire
- Wear eye protection at all times during testing
- Test fluid can pierce the skin and cause serious injury
Procedure
- Isolate each fuel injection nozzle one at a time to determine the malfunctioning nozzle.
- Start the engine.
- Loosen each fuel line nut one at a time at the fuel injection pump.
- Use a cloth to prevent fuel spraying on hot exhaust components. Tighten each nut before loosening the next.
- A faulty nozzle is indicated when exhaust smoke is partially or completely eliminated and performance is unaffected.
- Remove suspected nozzle and install a new nozzle to determine if removed nozzle is faulty.
- Clean, inspect and test nozzles. Do not use a wire brush. Use 8S-2245 Injector Cleaning Tool Group.
Tools required
- 8S-2245 Injector Cleaning Tool Group Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Caterpillar C3.3 →, Caterpillar C4.4 →
Source: Caterpillar owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.