Jerky throttle responce.

Hey all. Got a problem with my 03 VFR800A that I am stumped on. Hoping this is normal and someone knows what is going on before I tear it apart!! She currently has 14k on her, new chain, new brakes and fluid, new tires, lowering link and a power commander. Not sure what else as I have only had the bike 2 months!

Occasionally when holding a steady state speed with constant throttle input the bike will act like i just reduced throttle and slow down. If i add power to maintain speed it will jerk as it powers back up. I have braced my hand and throttle and noticed the bike will eventually start to speed back up on its own, but only after about 30sec-1min and loosing 20mph or so. No lights come on, no noticeable running problems. I have seen lots of forums on electrical problems that I am not ruling out, but all of them seam to have rough running problems associated with them.

If anyone can help isolate a few problems for me that would really be helpful!!

Thanks again..

 

You might want to reload the map and check for the O2 eliminator
My got jerky and back fire from time to time. I decided to clear all the map and reinstall the map and the problem go away. Hope this help

 

Did not know about O2 thing. Will look into that. Thanks. Have not looked yet, but am I able to just unplug the power commander to help eliminate it as a problem, or are they hard wired in?

 

It's a plug-in type of device, so you can temporarily remove it. It plugs inline with the ECU and wire harness, so you can unplug it and reconnect the two ends that it goes between. Should be on the right side of your bike.

 

You can un plug the PCIII but you have to reinstall the original connector to run without the PC

 

Is this connector a separate piece or like OOTVS stated?

 

Yes just like Ootvs stated

 

Update.

1. Ok. I unpluges the power comanderand pulled apart, cleaned and applied electircal greese to all conections on right side of bike. Took it for a ride and no problems yet. This is a interment problem so cant say its fixed yet!

2. I noticed the PO did a modification to the air box. Unpluged and caped off a hose on top of the box and unpluged and coverd a connector on the rear of the airbox. Has anyone else done this mod and could this be a factor to my current problem?

Thanks again

 

That's the PAIR mod. The PAIR system injects fresh air into the exhaust and can cause the bike to run poorly as the 02's will report lean condition and make the bike dump fuel.

 

It's been over done actually. This is really only to allow more airflow and increase induction noise. You can restore the flapper control by returning the vacuum hose back onto the flap actuator (if it's still there) and that will allow the air box to return it's original state of functionality. Note that you will hear a "knocking" sound once you've returned this back to normal, this sound is the flapper opening/closing and is normal. If the snorkel is gone, then you'll have to have that replaced. The covered connector at the back of the air box sounds like it's the PAIR valve hose connection and if that's been removed, no harm, no foul. This actually needs to be disabled or removed if you get the bike dyno-tuned.

 

amc401, so are you all good to go now? My bike is doing something similar so I wanted to see if you nailed down the exact fix.

 

So far so good. I noticed while removing the mods that the O2 eliminator that was done was slightly corroded on the resistor connection. Its been about 1000 miles with no problems since, so I plan on re programming the power commander and putting a different O2 eliminator on instead of just the radio shack resistors.

 

Good to know the bike run well :thumbsup: