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YZ450F No start - Bad injector?

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A little background on what has happen with the bike first. Last fall I was at the the track to ride, warmed up the bike and went out for the first lap. The bike died before the end of the lap, acting like it was running out of fuel. Kicked it over and it sputtered to life a bit then died again. The bike has not ran since. I am finally taking a look at it now, as it is spring and time to ride!

 

Things that I have checked on the bike:

1) TPS - Ohms out near spec at 6.3K ohms. With tuner connected it goes between 0-85% (not sure why not 100%)

2) Fuel Pump - Tested fuel pump pressure and received 45psi.

3) Spark - Checked for spark and changed the spark plug ( there is spark).

4) Ground - I did notice the ground was off (bolt must of came out) near the right side radiator. Connected that, still no start.

5) IAT and water Temp - Both are accurate according to the tuner. 

6) Injector - Tested at 11.6 ohms iirc spec is 12.0 ohms.

7) Starting fluid - The bike does run with starter fluid sprayed into throttle body. This Confirms engine has not mechanically failed. 

8) Code 39 - Code 39 is injector circuit. 

So with all of this I am thinking its the injector due to the code 39. I tried to listen to the injector firing but that is hard to do by your self. Is it common to have injector fail on these? I usually run 91 with 0% ethanol. What about possible ecu failure? I dont want to throw parts at it trying to fix it. 

 

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The injector circuit includes the run of wire that leads to and from the ECU to the injector and back, not just the injector.  Run a continuity check on the wiring and verify clean contacts.

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After miss-interpreting the wiring diagrams I am thinking its the ECU. I thought I had a bad wire going from the injector to ecu, turns out that is fine. Checked out all the grounds and they are good. I am thinking that the ground came off the bike and I fried something. The only other thing it could be the rectifier/regulator because I cannot test that. The ecu does fire up and can check stuff with the tuner connected though. I also still have code 39 which leads me to those to devices also. As the rectifier/regulator supplies voltage for the injector and the ecu must ground it. 

 

Edited by jc6711

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Hi guys, I have the exact same issue except for the code 39.

What did you find to be the problem ? 

Cheers 

 

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