MerCruiser Low-Pressure Fuel Pump Kit 866170A01 | Gen III Cool Fuel V8
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Low-Pressure Fuel Pump Kit — Part 866170A01
| Part Number | 866170A01 |
|---|---|
| Brand | Mercury Marine / MerCruiser / Quicksilver |
| Official Product Type | Low-Pressure Electric Lift Pump Kit |
| System | Fuel System — Gen III Cool Fuel Module |
| Pump Type | Electric low-pressure lift pump (tank to module) |
| Pump Reference | 866170T01 |
| Aftermarket Cross-Reference | Sierra 18-8865, REC866170A01 |
| UPC / GTIN | 745061659872 |
This is the genuine OEM low-pressure electric lift pump kit for MerCruiser GM-based V8 sterndrive engines equipped with the Gen III Cool Fuel module. The lift pump draws fuel from the boat’s fuel tank and supplies it to the Cool Fuel module, where a separate high-pressure pump (866169T01) then delivers pressurized fuel to the EFI injectors. One pump is required per module.
Two-stage system note: The Gen III Cool Fuel module uses two separate pumps — a low-pressure lift pump (this part) and a high-pressure pump (866169T01). Proper diagnosis to confirm which pump has failed is important before replacing either component, as symptoms of low fuel delivery can come from either stage.
Part Number Reference
- Current OEM kit number: 866170A01
- Pump reference: 866170T01
- Aftermarket: Sierra 18-8865, REC866170A01, REC866170A01K
Compatible Applications
Fitment requires the Gen III Cool Fuel module. Engines with the same displacement may use a different fuel system. Confirm by engine serial number and the applicable fuel module diagram.
- 5.0L / 305 CID V8 — Selected MerCruiser sterndrive applications with Gen III Cool Fuel module
- 5.7L / 350 CID V8 — Selected MerCruiser sterndrive applications with Gen III Cool Fuel module
- 6.2L / 377 CID V8 — Selected MerCruiser sterndrive applications with Gen III Cool Fuel module
- 8.1L / 496 CID V8 — Selected 496 MAG MerCruiser sterndrive applications with Gen III Cool Fuel module
- 8.2L / 502 CID V8 — Selected MerCruiser sterndrive applications with Gen III Cool Fuel module
When This Part Needs Replacement
- Fuel supply to the Cool Fuel module is weak or intermittent under load
- The pump no longer runs when commanded by the ECM
- The engine experiences fuel starvation or lean conditions at higher RPM
- Hard starting is traced to inadequate low-side fuel delivery pressure
- Fuel-pressure testing isolates the low-pressure stage as the fault
- Corrosion, electrical damage, or contamination is found at the pump or its connector
Related Parts
- 866169T01 — High-pressure fuel pump assembly (the other stage of the Gen III Cool Fuel module — search by part number)
- Mercury Quicksilver 892681 Fuel Pressure Regulator — MerCruiser Gen III MPI Fuel Module
- 8M0056175 — Wiring harness assembly (search by part number)
Installation Notes
- Relieve fuel-system pressure before beginning service
- Disconnect battery power before working on the fuel module
- Inspect electrical connectors and fuel hose connections for corrosion or damage
- Check the Cool Fuel module housing for contamination or internal corrosion
- Replace any damaged seals as required by the MerCruiser service procedure
- Verify fuel pressure at both the low- and high-pressure stages after installation
- Inspect carefully for fuel leaks before returning the engine to service
Parts Desk Insights
Most common customer issue: Replacing this pump when the actual fault is in the high-pressure stage — or vice versa. Because the Gen III Cool Fuel module uses two pumps in series, fuel starvation symptoms can come from either stage. A fuel-pressure test at the correct test port will identify which pump is underperforming before parts are ordered. If you need help diagnosing, send us your engine serial number and describe the symptom.
Best use case: Ideal for owners of Gen III Cool Fuel-equipped MerCruiser V8 sterndrives experiencing fuel delivery issues at higher RPM or under load, or for proactive replacement during a full fuel module service. The 496 MAG is one of the most common applications for this pump. If the module is being fully serviced, consider replacing both the low- and high-pressure pumps (866169T01) and the pressure regulator (892681) at the same time.
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
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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.
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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.
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