[Tomyboy650]

Hey. I have a problem with f650gs 2003 injection it is not opening when trying to start the bike. If i put the injector directly to 12v it opens and sprays fuel. On the injector conector have 9.8 v i think its not enough to open it? Any ideas?

 

[Godoh]

Check the connectors in the wiring loom that go to the injector, also check the earth connection on the battery and engine.
Sounds like you have a voltage drop problem, so check the connectors are clean and check voltages along the way to the injector.
Pete

 

[Godoh]

I just had a thought, if you are measuring that voltage when you are cranking the bike with the starter, that is about the best you can expect.
The other thing to try is another battery. The battery may be failing under load and these bikes are very prone to giving up the ghost when the battery is weak.
Good luck
Pete

 

[Buzz]

I agree with Pete - 9.8v sounds acceptable during cranking so if the injector isn't operating it's suggests either you're losing voltage across the plug (try cleaning the connections up) or the injector is the problem.

Cleaning and tightening all connections and installing a new battery might help nudge the voltage up a bit, enough to get it working?

Out of interest, how did you measure the voltage at the plug - I'd expect it only to be up for fraction of a second at a time so not sure a multimeter would pick it up? Did you use a 'Max' function?

EDIT: I just looked up the section on fuel injectors on the Crossroadz website. They show a resistance of around 15 Ohms. You could check the resistance of yours. Potentially, if it's high, you won't have enough voltage to energise it?

Buzz

 

[rowlett1951]

I agree with Pete - 9.8v sounds acceptable during cranking so if the injector isn't operating it's suggests either you're losing voltage across the plug (try cleaning the connections up) or the injector is the problem.

Cleaning and tightening all connections and installing a new battery might help nudge the voltage up a bit, enough to get it working?

Out of interest, how did you measure the voltage at the plug - I'd expect it only to be up for fraction of a second at a time so not sure a multimeter would pick it up? Did you use a 'Max' function?

EDIT: I just looked up the section on fuel injectors on the Crossroadz website. They show a resistance of around 15 Ohms. You could check the resistance of yours. Potentially, if it's high, you won't have enough voltage to energise it?

Buzz

Actually the 12 volts is present at the injector all the time, and the ground side is pulsed by the control unit.

 

[Buzz]

Good point Rowlett1951.
So could check for 12v at the injector with ignition ON before cranking. If only 9.8v then seems a bit low - maybe poor battery or poor connection somewhere?
Also means the other thing to check would be the crank position sensor is working to generate the fuel pulse.
Are you seeing a spark when you turn the motor over? Same signal used for fuel and for spark I think.

Buzz