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Bad fuel pump symptoms?

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For those with an 09, what are the symptoms you had when you have had a bad fuel pump?

I have had clogged fuel filters, need to know if the bad pump has a different symptom.

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The sympton would be fuel starvation. The pump is electric and generally they run or they don't. That doesn't mean that it can't be defective and run at a lower speed and cause low fuel pressure.

When you say you have had clogged filters before, do you mean on the 09/10 bikes, or just clogged fliters in general?

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09 clogged fuel filter.

Now confirmed I have low fuel pressure for starting. it is either a filter, pump or lack of electrical power to the pump.........

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A filter would be an easy inspection versus a voltage and pressure diagnosis.

I do recall a member trying to match up an 09 fuel pump with one from a rice burner. But I don't recall if he had a defective pump, or was preparing for eventual failure.

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OK so its not a fuel filter. I put in a new one and I always filter my fuel anyway.

Now after a short ride the symptoms are won't start without some throttle and will not idles (even with the idle screw would right out).

Interesting the bike runs beatifully up to wfo 👍

So weak pump or weak power to the pump?

Anyone want to guess before I start spending?

Is there a way to check the power source ?

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Do you have another friend with an 09/10? Best way is to get a graduated cylinder, take your fuel line off and put it into the cylinder. Hook your pump up to a separate power source (one other then the bike obviously) and see how much fuel it pumps out in a certain predetermined mount of time. I.E. How many oz's or cc's it pumps out in exactly 10 sec. Then use a friends bike and run the same test and see if his puts out more. If his puts out a descent amount more then theres your answer, weak fuel pump. I have never seen looked at a manual for this particular bike but alot of times on bikes with fuel pumps they should give and actual amount of fuel that it should pump out in a certain amount of time rather than having to test against a friends bike. Problem is this is pretty much the only way to test the pump for being weak. You can check the power but if its got low voltage than its a wiring problem and its more then likely that your stator is bad. The pump will only take what it is given, it does not demand power. It is either on or off there is no difference between idle and w.o.t in the amount of fuel it pumps, thats why we have injectors that determine the amount of fuel allowed into the motor.

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OK so its not a fuel filter. I put in a new one and I always filter my fuel anyway.

Now after a short ride the symptoms are won't start without some throttle and will not idles (even with the idle screw would right out).

Interesting the bike runs beatifully up to wfo 👍

So weak pump or weak power to the pump?

Anyone want to guess before I start spending?

Is there a way to check the power source ?

to check your power source your going to have to get the bike running and while idling use a volt meter to check the voltage going into the actual pump. Again as I stated before, if this voltage is low first thing I would have to guess is that your stator is going bad.

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Should be possible as I can get it to run with a bit of throttle. I assume it should be 12V to the pump even at idle?

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So the bike runs fine once you get going but wont run good when you first start it up? If I were you I would check the Air temp sensor. If you look at the bottom front of your air box right below the boot that connects the air box and the throttle body there should be a sensor right there that sticks into your air box. usually it is just held in by a twist like type of connection. I would take that sensor out and make sure that its nice and clean (if its dirty then use brake cleaner to clean it) and see if that helps. I would tell you to check it but you would need a computer and all that fun crap to do it so dont worry about checking it, just at least make sure its clean.

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Symptoms

Will only start with part throttle

Will only run if part throttle or more

Runs fine up to WFO (rev limiter)

Looking at the fuel bypass it seems to be pumping plenty of fuel - IMS clear :jawdrop:

Pulling the start knob makes no difference

No MIL lights

I cleaned the Air sensor - no change.

👍:banghead:🤣:banghead:🙂:banghead::applause:

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well then......with steady fuel flow I dont know what else would make it do that. Havent had much experiance with the new Fi bikes. sure its maybe not a severe clutch slip or something?

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Yep got me stumped.

Could be stator at low rpm

Could be rectifier

Could be supply to pump (by pass fuel rates look fine)

Could be weird sensor stuff - TPS, IAT, Etc (no Mil lights)

....

Thinking the only way to find out is to change out parts. Wish I had a spare bike to pilfer. Will be expensive to do it part by part.

Do honda have a diagnosis tool?

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It was my ECU. The way I found it is I got a tuner to try and communicate with the ECU using the Honda tool. It would not communicate. I bought a 2010 ECU which was cheaper than a 2009 here in Australia. Bike now starts 1-2 kicks cold or hot and runs sweet.

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