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Posted: Sat Feb 21, 2009 9:26 pm
by speedymike136
I bought a fx400 a couple months ago and im having an issue with it idleing very high. Im not sure how high it is cause i dont have any way of reading the rpms but is way higher then anything else ive ever owned. I have read tons of posts on here trying to figure it out but no luck. I checked the o-rings in the fuel line and all of the boots are on the tb the right way and not leaking at all. what else could it be? also where can i get a mil tool? will that help somehow? Any help would be really appreciated

Posted: Sat Feb 21, 2009 9:46 pm
by Canniboomer
The fuel line O-rings that you can physically see would not cause that -- those 2 merely prevent leaking while connected, but do not act to cause a possible spike in fuel pressure. The common problems are internal within the 4 disconnects, and the 4 buried O-rings -- with the tiny flow-path, and different symptoms depending which side gets worse - faster. You could also have interfered linkage, a hung up cable sheathe, a corroded return spring, non-lubed cable, screw turned up too high, etc... But machines with a bad suction flow have to idle exaggerated higher, (yes even from the factory), just to hold idle and still perform when you stab it. Opening the fuel path certainly allows for a smoother lower idle, and closer to other machines.

I have the MIL Tool, which is very handy if you are staying with the 500 ECU setup. It's probably better to just call, since there so many issues with a stock FX400 by now -- and even what was "stock" really varies on your machine.

Posted: Sun Feb 22, 2009 3:16 am
by thedeatons
Idle should be 2100-2200 rpm, so chances are it is supposed to be higher than anything you have ever owned....Anything I have owned either! LOL