I have a 2004 636 im having trouble with, the bike won't rev past 9k in neutral or under load. I've already began trouble shooting and here's where I stand; fuel pump torn down, cleaned filter and tested its running 43 psi, checked resistance on tps crank and cam sensors all checked out, 2 coils were high on primary resistance so I replaced entire set and spark plugs as well as air filter too, however I'm still having the same problem, if I hold the throttle wide open it hits 8-9k and the throttle bodies then close off and drops to roughly 3k and sits until I release throttle. Ive spent days on just about every forum site I can find and none of them narrow down far enough to help me, or the guys give up and take the bike to a shop, any help would be greatly appreciated. Thanks!
04 zx6r throttle issues... HELP!
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Your secondary throttle plates should be full open at high revs. Kinda strange that it closes down. That actually could be your problem and is prolly choking ur bike. Try unplugging the connector to it and leave them in the full open position. Then test ur bike to see if it makes a difference.
Also I've cleaned the fuel screen a few times just to make sure there is no restrictions and every time I hook replace the pump and line to start the bike it revs up where it should for a few seconds, is it possible the fuel pump drops pressure off and is too weak to supply a constant psi? Like I mentioned above it held 43 psi consistently with a gauge
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Your fuel pump seems like its fine. But what do u mean by primary valves closing off? Those are directly hooked up to your throttle by a cable. It is basically controlled by the twist of ur hand. Nothing else can move it. At full throttle they sould be fully open unless there is a misadjustment of some sort?
Ok so I left the secondaries open and yes you're correct the primaries stay open with throttle, however that made no difference, when held open I can se fuel going into every cylinder, it's almost like it's loading up as in not burning the fuel being supplied
Battery connections are good, all my switches are bypassed. I'm thinking it's an ecu issue not translating the signal sent from the air/fuel related sensors which is causing a timing/misfire in the ignition system. That's all I can think of because I've checked everything fuel related and when the throttle is held open you can see the fuel going into each cylinder it's just not burning it and with brand new coils and plugs I know it's getting proper spark discharge in each cylinder. Bike has 24,000 miles but it ran great last year up until late November then this started. I checked compression and every cylinder checked out good.
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When is your fuel pump discharge pressure showing 43psi? Just on startup, or consistently through running?
Have you done the fuel pump volume test? If not, check that. Because my old pump showed the correct pressure when it primed, but failed the volume test quite spectacularly. And it also would cut the engine around 9k rpm.
Have you done the fuel pump volume test? If not, check that. Because my old pump showed the correct pressure when it primed, but failed the volume test quite spectacularly. And it also would cut the engine around 9k rpm.
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