Mercury V8 250 User Manual

Fuel System
Section 7B - Troubleshooting and Diagnostics
Table of Contents
Fuel Component Troubleshooting and Diagnostics........... 7B-2
Antisiphon Valves....................................................... 7B-2
Fuel Supply Module (FSM)......................................... 7B-2
Fuel Lift Pump ............................................................7B-2
High‑Pressure Fuel Pump.......................................... 7B-3
Fuel Pressure Calculations, Engine Running............. 7B-4
Fuel Injector Resistance Test..................................... 7B-4
Wire Color Code Abbreviations.................................. 7B-5
Fuel Injector Circuits................................................... 7B-6
Troubleshooting and Diagnostics
90-8M0146617 eng JULY 2018 © 2018 Mercury Marine Page 7B-1
7
B

Mercury V8 250 Specifications

General

Engine Type	V8
Horsepower	250 HP
Displacement	4.6L
Fuel Induction System	Electronic Fuel Injection (EFI)
Steering	Hydraulic Steering
Gear Ratio	1.75:1
Cylinders	8
Starting	Electric Start
Full Throttle RPM Range	5200-6000 RPM
Alternator Amp	85 amp
Shaft Length	25 in
Weight	527 lbs
Fuel Type	Unleaded 87 octane minimum