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Discussion Starter · #1 ·
I have a 2015 cbr300r that is not getting fuel for some reason. The bike has spark and will start when spray small amout of fuel manually. I replaced the whole throttle body assembly thinking maybe a bad injector. There is fuel from the tank to the line that hooks tothe throttle body. And a guy tested to make sure the injector is spraying but from there its not firing. Idk why. Wondering if the throttle position sensonr may have got lose and could cause it not to fire or if the fuel pressure regulator has something to do with it or possibly an other sensor could keep it from firing. Just wanting to get any friendly ideas that i could check. Thank you guys/gals for any feedback!
 

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Discussion Starter · #2 ·
Possibly a bad sensor?????bad ecm??? Im thinking it has to be an electrical issue seeing how it has spark and will start, new fuel pump assembly, new throttle body assembly. Im at a lose and am looking for an option i can look into to get this back on the road,
 

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Possibly a bad sensor?????bad ecm??? Im thinking it has to be an electrical issue seeing how it has spark and will start, new fuel pump assembly, new throttle body assembly. Im at a lose and am looking for an option i can look into to get this back on the road,
You need fuel, spark and compression for the engine to run. You seem happy that the bike has spark and fuel but is it getting enough air for correct fuel mixture? Have you checked the airbox is free of restrictions and that the air filter is not clogged. If in doubt remove it and try starting.
Also, have you done a compression check? I don’t know the specs but this is a must do to eliminate that possibility.
 

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Discussion Starter · #4 ·
You need fuel, spark and compression for the engine to run. You seem happy that the bike has spark and fuel but is it getting enough air for correct fuel mixture? Have you checked the airbox is free of restrictions and that the air filter is not clogged. If in doubt remove it and try starting.
Also, have you done a compression check? I don’t know the specs but this is a must do to eliminate that possibility.
Thank you for a response, yes on the compression check and the air box is clear and clean also new air filter. The bike will atart if fuel is sprayed directly through the box. I am going to replace the fuel pump relay next. I have a new throttle body assembly on it new injector new after market quantum t35 fuel pump also. For aome reason the bike is not letting enough fuel or tje injector isnt getting proper voltage maybe to fire.it is puzzling. Anything you can think of other than a new fuel pump relay let me know. Would the throttle position module have anything to do with why there not enough fuel getting sprayed to start? I did test the injector and it does spray but in my option there wasnt alot of spray and i never teated the pressure so idk.
 

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Thank you for a response, yes on the compression check and the air box is clear and clean also new air filter. The bike will atart if fuel is sprayed directly through the box. I am going to replace the fuel pump relay next. I have a new throttle body assembly on it new injector new after market quantum t35 fuel pump also. For aome reason the bike is not letting enough fuel or tje injector isnt getting proper voltage maybe to fire.it is puzzling. Anything you can think of other than a new fuel pump relay let me know. Would the throttle position module have anything to do with why there not enough fuel getting sprayed to start? I did test the injector and it does spray but in my option there wasnt alot of spray and i never teated the pressure so idk.
Sorry my experience with fuel injection is limited. I've been lucky in that all the bikes I've owned have never had an EFI issue. Have you done this simple electrical check and cleaning procedure on the injector?
 
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