879312003 MerCruiser fuel injector with black composite body, electrical connector and fuel rail seals

OEM Reference: 879312003

MerCruiser® 879312003 Replacement Fuel Injector

Name: MerCruiser® 879312003 Replacement Fuel Injector
Brand: Discount Marine Parts Direct
SKU: DMP-879312003

DMP Part #DMP-879312003

OEM Reference879312003

Qty Required8 (verified V8 applications). Verify for 4.3L V6 — not confirmed.

Sourcing in ProgressReplacement Product Sourcing in Progress

879312003 applies to later ECM-555 MPI production from approximately 2007–2008. Earlier ECM-555 production (serial below 1A063240 for 4.3L; below 1A064825 for 5.0L / 350 / 6.2L) used a different injector — OEM 885176. Verify your exact engine model, serial number, and existing OEM injector reference before ordering.

MerCruiser® ECM-555 engines may use different injectors depending on engine model and serial range. A 4.3L, 5.0L, 5.7L/350 or 6.2L engine cannot be matched to an injector by displacement alone. Always verify using your engine serial number and existing OEM injector reference.

Engine Applications

The following application relationships are verified against Mercury Marine primary source documentation. Serial ranges are exact as supplied — do not generalise across variants. Verify your exact engine model, serial number, and existing OEM injector reference before ordering.

Engine Model	Years	Serial Range	Status
MerCruiser® 350 MAG MPI ECM-555 — 350 V8	2007–2008	1A064825 and up	✓ Verified
MerCruiser® 350 MAG MPI DTS ECM-555 — 350 V8	2007–2008	1A064825 and up	✓ Verified
MerCruiser® 350 MAG MPI Horizon ECM-555 — 350 V8	2007	1A064825–1A299999	✓ Verified
MerCruiser® 350 MAG MPI Horizon MIE ECM-555 — 350 V8	2007	1A064825–1A089999	✓ Verified
MerCruiser® 350 MAG MPI MIE ECM-555 — 350 V8	2007	1A064825–1A089999	✓ Verified
MerCruiser® 5.7L MPI Horizon MIE ECM-555 — 350 V8	2008	1A090000 and up	✓ Verified
MerCruiser® 5.7L MPI MIE ECM-555 — 350 V8	2008	1A090000 and up	✓ Verified
MerCruiser® MX 6.2L MPI ECM-555 — 377 V8	2007	1A064825–1A299999	✓ Verified
MerCruiser® MX 6.2L MPI DTS ECM-555 — 377 V8	2007	1A064825–1A299999	✓ Verified
MerCruiser® MX 6.2L MPI Horizon ECM-555 — 377 V8	2007	1A064825–1A299999	✓ Verified
MerCruiser® MX 6.2L MPI Horizon MIE ECM-555 — 377 V8	2007–2008	1A064825 and up	✓ Verified
MerCruiser® MX 6.2L MPI MIE ECM-555 — 377 V8	2007	1A064825–1A089999	✓ Verified
MerCruiser® MX 6.2L MPI MIE DTS ECM-555 — 377 V8	2007	1A064825–1A089999	✓ Verified
MerCruiser® 4.3L MPI ECM-555 — 262 V6	2007–2008	1A063240 and up	✓ Verified
MerCruiser® 5.0L MPI ECM-555 — 305 V8	2007–2008	1A064825 and up	✓ Verified
MerCruiser® 5.0L MPI DTS ECM-555 — 305 V8	2008	1A064825 and up	✓ Verified

Technical Specifications

Specifications are under verification. Fields will be updated as OEM and manufacturer data is independently confirmed.

OEM Reference879312003

Superseded OEM ReferenceVerification in Progress

Injector ManufacturerVerification in Progress

Manufacturer Part NumberVerification in Progress

Flow RateVerification in Progress

Operating PressureVerification in Progress

Electrical ResistanceVerification in Progress

Connector TypeVerification in Progress

Quantity Required (V8)8

Visual Identification

Visual identification details — body colour, connector type, and manufacturer markings — are under verification. Remove an existing injector and compare physical characteristics against confirmed OEM documentation before ordering.

879312003 MerCruiser fuel injector identification views showing black body, electrical connector, seals and injector ends

Compare the injector removed from your engine with the identification views shown here. Visual similarity alone does not establish fitment. Verify the OEM part number, engine application, and serial-number range before ordering.

What's Included

Package contents will be confirmed once a verified replacement product is sourced. Injector O-rings and seals are typically sold separately — inspect and replace as needed.

How to Verify Fitment

Step 1.Confirm the full MerCruiser engine model designation — not just displacement. ECM-555 covers multiple engine families across different production periods, and the same displacement may use a different injector depending on serial range.

Step 2.Locate the engine serial number plate and record the serial number. For 4.3L engines, the 879312003 applies from serial 1A063240 and up. For 5.0L, 350 Mag, and MX 6.2L variants, from serial 1A064825 and up (varies by variant).

Step 3.Remove one existing injector and read the OEM part number stamped or printed on the body. This is the most reliable confirmation of the correct replacement.

Step 4.Cross-reference the OEM number against the ECM-555 generation matrix before ordering. If your serial number falls below the 879312003 range, the earlier 885176 may apply — verify before ordering.

Customers Replacing This Part Also Consider

These parts are not necessarily required — inspect related components and replace only as needed.

MerCruiser® 885176 — Earlier ECM-555 GenerationSourcing in Progress

Injector O-Rings & SealsSourcing in Progress

All Marine Fuel InjectorsBrowse catalog

ECM-555 MPI All PartsBrowse engine family

Engine-Specific Related Components

Related components are grouped by verified engine application. Recommendations are derived from the compatibility matrix — not generic cross-sells. Verify your engine model and serial range before ordering any related component.

Related OEM Service References

The following OEM reference is associated with 879312003 injector service. Displayed for informational purposes only. Not in stock — do not order based on this reference alone.

8M0046869Related OEM Injector Service / O-Ring ReferenceNot in stock — informational only

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MerCruiser® 879312003 Replacement Fuel Injector

MerCruiser® 879312003 Replacement Fuel Injector

Engine Applications

Technical Specifications

Visual Identification

What's Included

How to Verify Fitment

Customers Replacing This Part Also Consider

Engine-Specific Related Components

MerCruiser® 350 MAG MPI ECM-555 — 350 V8 — 2007–2008

MerCruiser® 350 MAG MPI DTS ECM-555 — 350 V8 — 2007–2008

MerCruiser® 350 MAG MPI Horizon ECM-555 — 350 V8 — 2007

MerCruiser® 350 MAG MPI Horizon MIE ECM-555 — 350 V8 — 2007

MerCruiser® 350 MAG MPI MIE ECM-555 — 350 V8 — 2007

MerCruiser® 5.7L MPI Horizon MIE ECM-555 — 350 V8 — 2008

MerCruiser® 5.7L MPI MIE ECM-555 — 350 V8 — 2008

MerCruiser® MX 6.2L MPI ECM-555 — 377 V8 — 2007

MerCruiser® MX 6.2L MPI DTS ECM-555 — 377 V8 — 2007

MerCruiser® MX 6.2L MPI Horizon ECM-555 — 377 V8 — 2007

MerCruiser® MX 6.2L MPI Horizon MIE ECM-555 — 377 V8 — 2007–2008

MerCruiser® MX 6.2L MPI MIE ECM-555 — 377 V8 — 2007

MerCruiser® MX 6.2L MPI MIE DTS ECM-555 — 377 V8 — 2007

MerCruiser® 4.3L MPI ECM-555 — 262 V6 — 2007–2008

MerCruiser® 5.0L MPI ECM-555 — 305 V8 — 2007–2008

MerCruiser® 5.0L MPI DTS ECM-555 — 305 V8 — 2008

Related OEM Service References