M925 Hard Start and fluctuating idle

[jwesley74]

Hi yall, got an NHC 250 that has been a hard start since I got it. I read all the posts on here about them being temperamental, but this is my 3rd truck in southwest FL. Previous 2 always fired off like they just shut off even if it sat for a couple weeks. This M925 has a hard start even if I try to restart after 10 minutes. Also, when idling it will idle around 550-600 then dip almost til it quits and then go back to normal idle. It will consistently do this. I've changed the fuel filter in the canister and checked the lines visually. I'm told it sounds like an air leak in the fuel line. Which is causing it to lose it's prime and contributing to the fluctuating idle. I'm told to pressurize the fuel tank with air and let sit and look for wet spots indicating the leak, if any. One thing to note is the manual primer pump does not work/pump. I pulled the plunger and replaced the o-rings but still nothing. I opened the petcock while pumping but nothing happens. I'm curious if this might be the source of the air leak??? Any suggestions? Anyone have a similar issue and corrected? Thanks for any input.

 

[GHall]

I had the same problem with the idle. Make sure the emergency shut off lever is open all the way.. I would open the petcock on the fuel canister and drain it all the way, close it completely, open the one at the primer then pump it for a long time. It took a while for my system to prime up. If that doesn't work then pressurize the fuel system and look for leaks.

 

[doghead]

Remove your pump, clean the check balls and needle.

Test it, reinstall it, prime your system correctly.

 

[Artisan]

Well, you found "a" problem, how about fix
that issue and eliminate it, needs to be done anywho,
and see what happens?

 

[73m819]

sounds like your sucking a TINY bit of air