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305-4891 Fuel Injector Wiring Harness for Caterpillar Engine C4.2 Excavator 319D 311DLRR
Restore reliable electrical performance to your Caterpillar 319D 311DLRR with the 305-4891 Fuel Injector Wiring Harness. Built as a direct replacement for the original part, it matches the factory routing, connector layout and length, so it goes in where the old one came out.
It is used with the C4.2 engine and is matched to that engine's sensor and connector layout.
Function Overview
Sitting under the valve cover or alongside the cylinder head, the injector harness works in one of the hottest and oiliest places on the engine. It delivers the high-current firing signals the injectors need, cylinder by cylinder, thousands of times a minute.
On a modern diesel, each injector opens on a precisely timed electrical pulse from the ECM. The injector harness carries those pulses, so its condition directly decides whether fuel is delivered at the right moment and in the right amount to each cylinder.
On Cat equipment, a damaged harness often shows up as active diagnostic codes before any visible failure, so replacing the wiring can clear problems that look like sensor or ECM faults.
Made to Last on the Job Site
The goal is simple: a harness that fits like the original and keeps working like it. Matching connectors, correct branch lengths and durable insulation mean stable performance and high reliability in daily heavy-duty use.
Installation Tips
- Note the cylinder order of each injector lead before disconnecting.
- Inspect injector terminals and nuts; tighten to the specified torque.
- Replace the valve cover gasket and any pass-through seals while you are in there.
- Clear codes and check that the engine runs smoothly on all cylinders.
Keep Your Machine Earning
Dealer lead times for wiring harnesses can stretch to weeks. Ordering a replacement in advance, or as soon as faults begin to appear, keeps your project on schedule and avoids rental costs for a substitute machine.
Check Fitment Before Ordering
Model names are not always enough to confirm fitment, because manufacturers sometimes change harness designs within a model's production run. Check the part number on your existing harness, or send us your machine model and serial number, and we will check it for you.
Warning Signs to Watch For
Typical signs include:
- Injector circuit fault codes on the monitor
- Black or white smoke from the exhaust
- One or more cylinders misfiring
- Hard starting and reduced power under load
When diagnostics point to a circuit fault rather than a failed component, replacing the wiring is often the most cost-effective repair.
Product Details
- Part Name: Fuel Injector Wiring Harness
- Part Number: 305-4891, 3054891
- Engine: C4.2
- Condition: Aftermarket new
- Product Weight: 1 kg / 2.20 lbs
- Brand: TOPARTS
- Feature: Strict quality control standards; stable performance and high reliability
Applicable Models
Caterpillar CAT Engine C4.2 Caterpillar CAT Excavator 319D 311DLRR 312D 312DL 314DCR 314DLCR 315DL 319D 319DL
Shipping and Payment
- Payment Method: PayPal, Stripe, Credit card, Visa, etc.
- Shipping Method: DHL, FedEx, UPS, TNT, USPS EMS, etc.
- Track Your Order: An email containing the tracking number with a link will be sent to you as soon as it ships.
Note: Please verify your part number and match our product pictures to your original item before ordering. If you have any questions, please feel free to contact us. Thanks.
