[Jh0nny_gsxr]

I ride my bike for like 45 min and it was perfect but i came to a stop and when i try to take off bike start hesitant bad (like misfire) to the point i stall 3x. The only way i could take of was having rpm over 4k and it jump bad like misfire until clear after 4k rpm was stable. So long story short below 4k rpm sound like misfire and hesitate hard, one i pass 4k rpm is like the bike is new.

I ready replace the following parts:

Stator
Rectifier
Battery
Spark plugs (2 different sets)
Ignition coil
Stva
ecu
Fuel pump
Fuel filter
Injectors
Oil
Replace vacuum lines on buddy throttle

Any idea or suggestion.

 

[TheGeek]

Take a video and load to youtube.

 

[Jh0nny_gsxr]

Take a video and load to youtube.

2004 gsxr 600 sound like misfire under 4k rpm. i need help

The image is not the best but i guess you can hear the misfire when i take off. It does clear after 4k rpm. I just remove the throttle body and replace the vacum lines and clear the whole body. issue remain if that video is not helpful on how bad it sound. I can re take another tomorrow

 

[TheGeek]

Might be time for a compression test. Did you just get this bike? You might want to just check the cam timing as well. If someone else got in there and tried to adjust and made a mistake, it can cause weird issues.

The other thing to try is unplugging sensors one at a time to let the ECM insert the static values. It could just be the ECM doing the right thing with bad data.

 

[Jh0nny_gsxr]

Might be time for a compression test. Did you just get this bike? You might want to just check the cam timing as well. If someone else got in there and tried to adjust and made a mistake, it can cause weird issues.

The other thing to try is unplugging sensors one at a time to let the ECM insert the static values. It could just be the ECM doing the right thing with bad data.

I hade the bike for like 6 month. But i hade ride it before multiple time and no issues prior. But ill look on the unplugging the sensor to test the ecm i already put a new one and didnt make a difference. I thought is call ecu but is the ecm what i put new as well hunting for the issue

 

[Jh0nny_gsxr]

I hade the bike for like 6 month. But i hade ride it before multiple time and no issues prior. But ill look on the unplugging the sensor to test the ecm i already put a new one and didnt make a difference. I thought is call ecu but is the ecm what i put new as well hunting for the issue

Update.

I just did a compression test and for some reason it show 60 psi on all 4 cylinder. I know it required 171 to 228 but why ones it pass 4k rpm have lot of power? Any idea or advice

 

[TheGeek]

At 4k rpm, the air doesn't have time to leak out before ignition.

 

[Jh0nny_gsxr]

At 4k rpm, the air doesn't have time to leak out before ignition.

So any idea why at take off it bug out (misfire) almost imposible to take off and now even more questions why it have 60 psi on all 4 cylinder but ones it pass 4k rpm it have lot of power like new?

 

[TheGeek]

I would have to put hands on it and perform some diagnostics. Also at low RPM, the engine has a higher vacuum. Could indicate a problem with the IAP hoses/sensor. You have to do the diagnostics.

 

[Jh0nny_gsxr]

I would have to put hands on it and perform some diagnostics. Also at low RPM, the engine has a higher vacuum. Could indicate a problem with the IAP hoses/sensor. You have to do the diagnostics.

I did and also replase the sensor and since i was in there i replace all vacuum hose

 

[Jh0nny_gsxr]

Problem have been solve. The tps was off. I bring it to a shop and they figured out

 

[peter079]

So any idea why at take off it bug out (misfire) almost imposible to take off and now even more questions why it have 60 psi on all 4 cylinder but ones it pass 4k rpm it have lot of power like new?

The 60psi is most likely you have the wrong type of compression tester. Not suitable for bikes.

The video sounds like a misfire, could be coils or injectors related. I'm leaning towards coils,
because you said it misfires under load and when hot. You said that you replaced all the coils. Were they new items?

Edit: ( I see you started another thread, so I will go there).