Mercury MerCruiser Fuel Pressure Regulator – Port Side | 885174
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Mercury MerCruiser Fuel Pressure Regulator – Port Side | 885174
Part Number: 885174 | Brand: Mercury / MerCruiser | Position: Port-Side Fuel Rail | UPC: 745061543447
Genuine Mercury Marine OEM port-side fuel pressure regulator for selected MerCruiser MPI gasoline sterndrive engines. Mounted directly to the port fuel rail in ECM 555 multi-port injection systems, this regulator maintains the correct fuel pressure delivered to the injectors — a critical factor in clean combustion, fuel economy, and reliable starting across the engine’s operating range.
Features
- Genuine Mercury Marine OEM replacement regulator
- Port-side fuel rail position — ECM 555 MPI fuel injection systems
- Maintains correct fuel rail pressure for injector operation
- Direct OEM fit — matches original mounting, connections, and sealing configuration
- Engineered for marine MPI fuel system demands
Compatible Applications
- MerCruiser 4.3L MPI — ECM 555 fuel injection system
- MerCruiser 5.0L MPI — ECM 555 fuel injection system
- MerCruiser 350 MAG MPI / 5.7L — ECM 555 fuel injection system
- MerCruiser MX 6.2L MPI — ECM 555 fuel injection system
Confirm the engine model, serial number, and ECM/fuel-rail configuration before ordering. MerCruiser used different fuel pressure components across MPI generations — matching by serial number and the applicable fuel-rail parts diagram is the most reliable fitment check.
When Replacement Is Needed
A failing fuel pressure regulator may contribute to hard starting, rough idle, hesitation, rich or lean running conditions, or fuel pressure readings outside specification. Perform a fuel pressure test to confirm the fault before replacement.
Installation Notes
Relieve fuel system pressure before beginning service. The regulator mounts to the fuel rail and must be installed with the correct sealing components and retaining hardware. Inspect the rail connection and seals carefully after installation, pressure-test the system, and verify there is no fuel leakage before operating the engine.
Cross-Reference Part Numbers
- Mercury / MerCruiser: 885174
- Sierra: 18-7662
- Mallory: 9-33210
- UPC: 745061543447
Parts Desk Insights
This regulator is most commonly needed on MerCruiser 4.3L, 5.0L, 350 MAG, and MX 6.2L MPI engines running the ECM 555 fuel injection system. The best use case is a direct OEM replacement confirmed by a fuel pressure test showing the port-side rail is out of specification. The most common customer issue is ordering without confirming the engine’s serial number range — because MerCruiser used different regulator configurations across MPI generations, matching by serial number and the fuel-rail diagram is essential before ordering.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.