Fuel Injector – Fits Mercruiser 8.1L/496 MAG/496 HO MPI Engines (Replaces 881693002, 3861278)

Fuel Injector – Fits Mercruiser 8.1L/496 MAG/496 HO MPI Engines (Replaces 881693002, 3861278)Fuel Injector Fits Mercruiser 8. 1L 496 MAG 496 HO MPI Engines This multi port fuel injector is designed for Mercruiser 8. 1L 496 cubic inch engines (including 8. 1S MPI, 8. 1L HO, 496 MAG, and 496 HO models) from 2004 and later equipped with Multi Port Injection (MPI) systems. It serves as a direct replacement for multiple OEM and aftermarket part numbers, including Mercury 881693002, 881693001, and 3861278. The injector features a metal housing and

Fuel Injector – Fits Mercruiser 8.1L/496 MAG/496 HO MPI Engines

This multi-port fuel injector is designed for Mercruiser 8.1L/496 cubic inch engines (including 8.1S MPI, 8.1L HO, 496 MAG, and 496 HO models) from 2004 and later equipped with Multi-Port Injection (MPI) systems. It serves as a direct replacement for multiple OEM and aftermarket part numbers, including Mercury 881693002, 881693001, and 3861278. The injector features a metal housing and a 3-hole disc nozzle based on the Delphi design, connecting via a standard Delphi Multec II electrical interface.

• Installation Method: Direct OEM replacement
• Fuel Compatibility: Gasoline
• Included Components: 1 x Fuel Injector with pre-installed O-rings

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1 x Fuel Injector (Replaces 881693002/3861278/25348180)

Installation Guide

1. Relieve Fuel Pressure: Safely relieve the pressure from the fuel system according to the manufacturer's service manual.
2. Disconnect Battery: Disconnect the negative terminal of the battery.
3. Disconnect Injector: Unplug the electrical connector and carefully disconnect the fuel line from the injector.
4. Remove Retainer: Remove the retaining clip or bolts holding the fuel injector in place.
5. Extract Old Injector: Gently twist and pull to remove the old injector from the fuel rail. Be prepared for minor fuel spillage.
6. Lubricate O-Rings: Apply a small amount of clean engine oil to the new O-rings on the replacement injector.
7. Install New Injector: Press the new injector firmly into the fuel rail until it seats correctly.
8. Secure Injector: Reinstall the retaining clip or bolts to secure the injector.
9. Reconnect Lines: Re-attach the fuel line and plug in the electrical connector.
10. Reconnect Battery: Reconnect the negative battery terminal.
11. Check for Leaks: Prime the fuel system by turning the key to the "On" position a few times, then check thoroughly for any fuel leaks around the injector before starting the engine.

Troubleshooting & FAQ

Q: How do I know if this fuel injector fits my 496 engine?
A: This injector fits MerCruiser 8.1L/496 MAG and HO MPI models from 2004 and later. Verify your engine model against the "Compatible Engine Models" table and cross-reference your existing part number with the numbers listed, such as 881693002 or 3861278.

Q: What are the signs of a failing fuel injector?
A: Common symptoms include engine misfires, rough idling, poor acceleration, increased fuel consumption, or difficulty starting. A fuel smell may also be present if the injector is leaking.

Q: Are these injectors the same as the original Delphi parts?
A: These are aftermarket injectors built to meet or exceed OEM specifications. They feature the same Delphi Multec II electrical connection and 3-hole nozzle design for compatible performance.

Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.