Yamaha 115 EFI hesitating when opening throttle

[bugmuncher]

Yamaha 115 EFI Four Stroke Year 2001. Starts easily. Idles nicely. When throttling up from idle, the engine hesitates and sometimes stalls. This can be avoided by throttling up slowly. Also return to idle seems a bit slow and a vacuum sound can be heard for a short while. (Not sure whether this is normal or not) Seems to occur whether engine is warm or cold. Otherwise runs well. IAC clicks when engine is turned off, so this seems ok. Have cleaned the injectors and VST and replaced filters. New fuel. New thermostat. Makes no difference.
I have searched for these symptoms, but cant find any info on this exact problem. Can anybody help?

 

[rogika]

Yamaha 115 EFI Four Stroke Year 2001. Starts easily. Idles nicely. When throttling up from idle, the engine hesitates and sometimes stalls. This can be avoided by throttling up slowly. Also return to idle seems a bit slow and a vacuum sound can be heard for a short while. (Not sure whether this is normal or not) Seems to occur whether engine is warm or cold. Otherwise runs well. IAC clicks when engine is turned off, so this seems ok. Have cleaned the injectors and VST and replaced filters. New fuel. New thermostat. Makes no difference.
I have searched for these symptoms, but cant find any info on this exact problem. Can anybody help?

Check the tps, (throttle position sensor).

 

[crazy charlie]

Are you sure you did ALL filters? I would start at the fuel water sep and work my way thru the motor.The filter in the vst would cause that issue.Also check you fuel tank vent for a clog.Charlie