Polaris ATV Forum banner
1 - 5 of 5 Posts

· Registered
4 Posts
Discussion Starter · #1 ·
2005 Sportsman 800 EFI
Have ongoing issues I cannot resolve. Replaced broken fuel pump and machine was running great. After two weeks of good use, while idling in my driveway it killed and wouldn't restart. Now will start and run for a few seconds but kills as soon as I touch the throttle.
Done so far:
  • Replaced fuel pump
  • Replaced fuel filter
  • Changed plugs
  • Oil and filter change
  • Replaced TBAP wiring harness
  • Used fuel pressure tester and cannot get good pressure off fuel rail
  • No Codes
  • Confirmed good spark
  • Confirmed good battery voltage

Starts with starter fluid
Confirmed good fuel into and out of fuel filter, can see strong pressure when cycling on the pump with the key.
Further down the line, very little pressure but definitely decent amount of fuel out of the test, schrader valve.

Appreciate any ideas or what to try next....

· Administrator
20,471 Posts
Flow and pressure are two different things - like volts and amps

You can have a battery with voltage, but as soon as current starts to flow the voltage drops - as an example, take two garden hoses of equal length, but of different diameters (one 1/4 inch and the other 1 inch) - connected to the same water source with say 30 PSI of pressure, with a 1/2 spray nozzle attached to each hose, which hose will flow more water and which hose will have the best pressure?

You may have flow, but fuel injection works off pressure - find the leak or blockage between the pump and the fuel rail and if none, install a new pump

· Premium Member
2008 800 ho efi, 2019 850 SP premium
16,729 Posts
Flow volume = amps
Pressure = volts
When you kink the line = resistance

It's that simple!
  • Like
Reactions: SAR Sportsman
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.