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Tyler Jane

"Fan" noise when starting ignition has stopped happening

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Tyler Jane
Ok, so, you know how when you turn your key to the on position, the dash does it's little light show and its accompanied by some kind of mechanical fan noise? What exactly is that extra noise? Because my bike stopped making that noise...
 
For awhile, it stopped making the noise just on cold start, but if I warmed up the bike, turned it off, then turned ignition back on, it would make the noise again. But now it's not doing it at all, ever.
 
So what is that noise? Should I be worried that it's not making it anymore? 
 
Bike runs fine otherwise.
 
EDIT: It's the fuel pump priming. I haven't been hearing it because my kill switch has been "Off" when I turn the key on. Before my ride home from work just now, I turned the kill switch on and then turned the key and I heard the pump prime just like it used to. Mystery solved.
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churchxd
Ok, so, you know how when you turn your key to the on position, the dash does it's little light show and its accompanied by some kind of mechanical fan noise? What exactly is that extra noise? Because my bike stopped making that noise... 
For awhile, it stopped making the noise just on cold start, but if I warmed up the bike, turned it off, then turned ignition back on, it would make the noise again. But now it's not doing it at all, ever.
 
So what is that noise? Should I be worried that it's not making it anymore? 
 
Bike runs fine otherwise.
Just a quick question before I answer. Have you been watching your engine temp?

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ducttapewd40
I'm guessing that's your fuel pump you're hearing.
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Tyler Jane
Just a quick question before I answer. Have you been watching your engine temp?
 
Yeah, I always keep an eye on it. Never gets high and the fan almost never kicks on while I'm riding. Generally temp stays around 160-190.
 
I don't know if the sound I'm hearing is actually a fan, it's just some kind of mechanical noise that I'm not familiar with.

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Tyler Jane
I'm guessing that's your fuel pump you're hearing.
Or, NOT hearing, as it were.  
 
If the fuel pump isn't priming, what does that mean to me? Wouldn't that just make it harder to start? Bike starts fine regardless.

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churchxd
Just a quick question before I answer. Have you been watching your engine temp?
Yeah, I always keep an eye on it. Never gets high and the fan almost never kicks on while I'm riding. Generally temp stays around 160-190. 
I don't know if the sound I'm hearing is actually a fan, it's just some kind of mechanical noise that I'm not familiar with.
Hmm the only other thing I can think of would be your fuel pump? And if it's still running thats working fine to.

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randy2100
The noise is the fuel pump pressurizing the line. It stops after a few seconds. Maybe it can tell when it's already pressurized.
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ducttapewd40
Also, your fuel pump won't kick on if your kill switch is still all the way up in the off position.

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Tyler Jane
The noise is the fuel pump pressurizing the line. It stops after a few seconds. Maybe it can tell when it's already pressurized.
Well, I don't hear the noise when I start the bike for the first time in the morning after it's been sitting all night, so I doubt it would be pressurized at that point. 
But I found this thread and I think it answers it: http://fz07.org/thread/1750/whirring-noise-when-turn-key?page=1
 
It seems like if the kill switch is set to Off when you turn the key, it won't prime. And I hadn't realized this, but I've started to use the kill switch to stop the bike recently (ever since I bought the akra pipe), because I often stop the bike while it's still rolling so that I don't disturb my neighbors as I pull into my driveway, or my coworkers as I pull into work.
 
I'll experiment with the kill switch after work to see if that's it. But regardless, bike has been starting fine every time despite the fuel pump not priming when you turn the key, so I guess I won't worry to much about it.

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Tyler Jane
Also, your fuel pump won't kick on if your kill switch is still all the way up in the off position.
Yep, I think that answers it for me :) 
Weird though that it still doesn't prime if you turn the kill switch to on after the key is turned. I guess it primes at the same time the starter kicks in when you pull the switch down all the way? I mean, it's been starting fine so I have to assume that's what it's doing.

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sorkyah
The noise is the fuel pump pressurizing the line. It stops after a few seconds. Maybe it can tell when it's already pressurized.
There is a fuel pressure sensor, fuel level sensor, and fuel filter integral to the fuel pump
 
the pump has an overpressure bleed(regulator)to exhaust excess back into the tank. the pump should run for 5-7 sec when the key is cycled on and the killswitch is not engaged
 
The killswitch removes the power feed to the fuel pump and fuel injectors

ATGATT... ATTATT, two acronyms I live by.
 

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rick
Likely that the sidestand switch and the clutch interlock when the bike is in gear also shuts off power to the fuel pump ( directly or thru a relay if there is one) as well as the ignition.
 
The tip-over sensor probably shuts off ignition and fuel as well.
 
This is pretty easily done with modern FI. The ECU usually controls everything thru the ground side of the circuit.

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rick
The noise is the fuel pump pressurizing the line. It stops after a few seconds. Maybe it can tell when it's already pressurized.
There is a fuel pressure sensor, fuel level sensor, and fuel filter integral to the fuel pump 
the pump has an overpressure bleed(regulator)to exhaust excess back into the tank. the pump should run for 5-7 sec when the key is cycled on and the killswitch is not engaged
 
The killswitch removes the power feed to the fuel pump and fuel injectors
Hmm, there might be a screen in the intake of the pump that'll keep chunks of grit out, but I don't think this bike actually has what I would call a fuel filter - there's none in the parts list and there's no scheduled maintenance - at least that I could find.  

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sorkyah
I believe its a sock type filter for the fuel pump and no separate part number avail as far as i can tell either

ATGATT... ATTATT, two acronyms I live by.
 

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ducttapewd40
Also, your fuel pump won't kick on if your kill switch is still all the way up in the off position.
Yep, I think that answers it for me :) 
Weird though that it still doesn't prime if you turn the kill switch to on after the key is turned. I guess it primes at the same time the starter kicks in when you pull the switch down all the way? I mean, it's been starting fine so I have to assume that's what it's doing.
Well I got curious enough I went out to the garage and played with it.  Mine works just the same way.  I could have sworn that the pump primed if the killswitch was flipped on after the ignition, but nope.  Either I'm crazy or my old R6 did and that's what I'm remembering.  Either way, you've got nothing to worry about.
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rick
Interesting. There still has to be pressure to the injectors, so that means the pump primes as the starter spins.
 
 

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Guest Ralph
Interesting. There still has to be pressure to the injectors, so that means the pump primes as the starter spins.  

Maybe that's why it sometimes seems to spin a bit longer on the starter. My last bike did not prime if the emergency stop was off but did as soon as
you switched it to run has you say it must prime as the starter turns.

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rick
My Aprilia will prime as soon as any of the nannies that would stop the motor are returned to run mode - sidestand, clutch, kill switch etc. It's hard to miss the sound, even through a big plastic tank filled to the top. The dash also reads "OFF", just in case you couldn't figure out why the starter wouldn't spin up.
 
The manual for that bike warns against routinely using the kill switch to stop the motor - lots of speculation as to why. No good answers, though everyone is paranoid enough about the Italian electrics (actually, it's a Spanish ECU, like older Triumphs) to use the ignition as recommended as much as possible - lol. .

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Mr.Puss
You need a new flux-capacitor...Clearly.

Crush your enemies. See them driven before you. Hear the lamentations of their women.

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