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No fuel getting to cylinder

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I've got a 2009 CRF450 that I just replaced the fuel filter, injector and adjusted the valves. I've gone through the throttle body completely and checked every connector. For some reason it will not get fuel. I tried unplugging the throttle position sensor cause I read that could be the problem and still nothing. I'm positive it is not getting fuel out of the injector when kicking. Any ideas? I have a feeling its the stator cause I've read a lot of people had the same issues and that was it. It does have spark though.:eek:

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Sounds like the fuel pump. Recently a friend had same issue on a '10 CRF250R. Turns out it would bump start, but he couldn't kick start it. Later found a capacitor had failed in the fuel pump. He replaced the pump and all set. May be worth having it tested if you can

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I actually pulled the fuel line off and kicked it over and it comes out right away so I don't think that is my problem. Anyone know how to test the stator?

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I've gone through the throttle body completely and checked every connector. For some reason it will not get fuel..:eek:

:smirk: not sure how to help

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Do you have a meter that can read DC HZ? I would suggest measuring the frequency and voltage at the injector when kicking.

Wire bl/bu and P/Y. Set your meter for min max DC and kick it. This will test if the injector is being fired electrically. Then again, you may not have fuel at the injector. It may be opening but the fuel has not made it's way to it.

Since the fuel pump is running it would seem the rectifier and stator are working.

I would also check the condenser to see if it holds a charge. The manual talks about a battery.. does that bike come with one? They probably mean to use a 12V battery and charge the condenser (capacitor). Remove battery power and check the voltage. Should be about 12VDC.

You may have enough power to run the pump but not the injector.

What is the history? It was running, you did some work, then it would not start? If so, check connections and if OK, kick kick and kick!

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I actually pulled the fuel line off and kicked it over and it comes out right away so I don't think that is my problem. Anyone know how to test the stator?

If its got spark and it pushes fuel out of the line, the stator is working.

Id kick it and measure the voltage at the injector connections. You probably wont be able to see shit though. Its a pulse, if you had a test light on the positive side you could see it flash...

One other thing, there were a lot of 09's that had bad injectors. And if youve got fuel too it, and spark...that leaves the injector itself.

You could pull the injector and kick it and see if fuel comes out. It should...just dont be lookin at it when you kick it...or have the plug wire off.

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I've that it can have spark and not enough power to make the fuel injection work therefore the fuel injection will not work. The fuel pump does work and the fuel injector is brand new.

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I've that it can have spark and not enough power to make the fuel injection work therefore the fuel injection will not work. The fuel pump does work and the fuel injector is brand new.

What?

We can offer assistance but if you don't try what is the use?

Don't worry about the injector turning on and off. It will pulse fast enough to read a steady voltage but it will be less than peak and more of an average when at a low frequency.

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So I just got back from checking the condenser, rectifier, and ECU unit on the same bike and everything checked out fine. Now what! lol The fuel injector is brand new along with the fuel filter and I kicked it over and the fuel pump is working. But it still isn't getting fuel. Just downloaded the service manual and tonight I'm going to try to test the output of the stator, but it does have spark to the plug. I've read that that doesn't matter cause it might not be powering the FI? Any suggestions?

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Ok Shawn I will do that. What if it doesn't have power there?

Make sure you measure across the injector. What this means is you want to measure from each side of the injector lead. I don't have the electrical diagram in front of me to see if the injector is switched with negative or positive. Typically they are switched with negative. This means the + VDC is always on to the injector. The circuit is completed through a transistor that closes to the negative lead to ground. If you use the common negative as a reference it would appear the injector is on, when it is not.

Your bike has 2 pickups and without the electrical diagram of the spark box I cannot tell you what purpose each serves. If I were to guess they are using one pickup to fire the injector and another to fire the ignition coil.

So, to answer your question: no injector current could be due to low voltage, bad condenser, bad spark box, wiring issue or a bad pickup coil.

Have you tried to push start it? Can these bike be push started?

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Yeah I tried push starting and no go. I have the manual now but don't really understand what they are talking about when testing systems. I could email you the manual if you want to take a look at it. I have a feeling my pickup coil is shot.

Like I said I just tested the condenser, ECU and rectifier on another 09 and they worked fine so its not those. It also has a brand new fuel filter and injector.

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Measure between pin 5 and 24 on the ECU and kick the motor. Problem is, I don't know what voltage would be there. I would need the injector part number on the side of it to tell you.

Check for a short between pin 14 and 19(set meter on low ohm's and post value. This is the kill switch. Should be open.

What was done to the bike previous to this?

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Ive never seen an injector that WASNT switched on the negative side. So he should be able to just plug the meter into the positive side and kick it and watch the voltage build.

He's got spark which means that pick up is functioning.

I tried unplugging the throttle position sensor cause I read that could be the problem and still nothing.

Did you ever plug the TPS back in?

The power wire on the injector is the pink Yellow one. The other wire on the injector is the ground wire they use to switch the injector on and off with. If you measure from that one with the red lead and the black lead of your meter to ground on DC you should get over 12+. If you check with with the meter set to beep for continuity, red lead on the injector black blue and the other to the engine, you should hear the meter beep when you kick it. Also, check the resistance on the injector itself. The range is 11.6 to 12.4 ohms.

Wow....Everything I just went through is on 6-29, and 6-30...I guess I should have read through it first... :lol:

The book shows you how to put 12V on the bike and test stuff.

All the sensors are 5V just like a car ( why wouldn't they be :) )

And looking at the differences from the 09 to the 2010, It looks like the engineers got what they wanted in the 09 and then a mechanic had to work on one and raised hell and they came out with the changes in 2010 to the wiring harness. :)

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The power wire on the injector is the pink Yellow one. The other wire on the injector is the ground wire they use to switch the injector on and off with. If you measure from that one with the red lead and the black lead of your meter to ground on DC you should get over 12+.

Not trying to muddy the waters here so bear with me.

It is not possible to measure voltage using a ground/common reference to a device that switches ground/common. You would be measuring itself. The only way to measure this is to connect the meter to any wire that is 12VDC and the other to the negative of the injector.

You may have meant to say(and I misunderstood): a way to see if 12VDC is supplying the injectors positive side is to measure the pink/yellow with reference to ground. This would mean the wire and voltage is good and the system is producing 12VDC but does not mean the negative side of the injector is switching.

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Not trying to muddy the waters here so bear with me.

It is not possible to measure voltage using a ground/common reference to a device that switches ground/common. You would be measuring itself. The only way to measure this is to connect the meter to any wire that is 12VDC and the other to the negative of the injector.

You may have meant to say(and I misunderstood): a way to see if 12VDC is supplying the injectors positive side is to measure the pink/yellow with reference to ground. This would mean the wire and voltage is good and the system is producing 12VDC but does not mean the negative side of the injector is switching.

Correct. After checking the source voltage good, then check the switch signal. If you end up with nothing, you've found your problem. :)

I'm kinda impressed with the service manual. I can see where it may go over some guys heads, but its done pretty well.

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A little update, I found out what my problem was. Turns out the o-ring on the seal inside the fuel pump was damaged causing the fuel pump to work but not enough to push through the injector. Replaced the seal and it runs like a champ!

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Had the same issue with our 09, had spark but no fuel, everthing checked ok electrically, found the pump was working (had good flow) but it wasn't building pressure, put a new pump in it & all was good...

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