Surging generally in low revs

Hi all, I have a 2010 vfr, right from new this bike has been "a pig" to ride. It is rough on low revs and occasionally surges mid range for no reason. The rough/surging at low revs is a particular problem, if I was not very experienced I am sure I would have come off the bike at low cornering speeds by now. Also if I raise the revs from idle very slowly it will make a slight noise under the air box at about 1500rpm and drop about 200rpm. I have ridden many bikes for long periods at a time over the years (about 20 or so different bikes) and never had one as rough as this. One of the bike I have ridden is a 97' vfr which I owned for 3years from new and was as smooth as could be - loved it. More recently a vtr1000 which compared to this bike was smooth as and could actually hold speed around a slow corner. Just to put the problem in more detail, I am often in peak hour traffic and at around 2500rpm the bike will surge, die and repeat over and over until I pull the clutch to stop it. If anyone can picture the girl that was attempting to learn to drive in the karate kid movie -that is what this bike is like with the surging. I have taken this bike to 2dealers for servicing and mentioned the problem but they both said it was fine. I have read alot about doing PAIR, PCIII, etc mods but this bike is still under warranty and the PCIII mod is expensive. Dam gsx 650's are perfectly smooth compared to this. I guess the questions are; Is thus usual for a vfr 800 2010 model? Are vfr's Just crap now days? Is there anyone i could take this bike to in Brisbane that will take me seriously?

 

Try checking all the plugs on the electrics. Occassionally a loose connection will do something similar.

Is it flashing any fault codes at you?
Is it getting very hot in traffic? normal traffic not Gateway traffic?

 

Throttle Position Sensor?

Don't the fuel injected bikes have a TPS that sends a signal to the control unit to indicate closed throttle (Idle) and WOT? The engine idle speed is regulated based upon that signal, engine speed, air temperature and engine temperature, and lambda sensor.

If the TPS is still indicating a closed throttle when in fact it it slightly open, the Idle Speed Control will still be functioning and fighting against what you want the engine to do. That is probably what is happening at 1500 rpm on the slow opening test you did--the ISC kicked out and the revs dropped after the TPS came off the Idle switch point. Maybe TPS needs adjustment.

Also it may be that either the engine temp or intake air temp sensor input to the control unit is out of spec since those are primary inputs to ISC.

The service manual has troubleshooting of sensors using a voltmeter, but if you don't have one you could disconnect the sensors one at a time to see if the problem goes away or gets worse running in limp-home mode. Try this both with a cold engine and when warmed up.

 

The Bike gets to 100 in temperature in traffic and once it gets there it pretty much keeps the cooling fan constantly on. This is winter though and early mornings / late afternoons so the ambient temperature is not very high. Last summer it did get up to 110 a few times, watched it carefully at those points because I believe 120 is when you really have to worry – this was not riding hard, at worsted it was up to redline on first gear then back to cruising revs (4,000-5,000).

I am not sure if it has a TPS of the VFR 2010 model – I will have to try and find the manual to read and check – has anyone got a 2010 mechanics manual? When starting cold the automatic choke operates correctly, starts easily and never backfires. But I can get the revs to drop as described almost all the time no matter if the bike is cold or hot– when I first started to ride this bike it would make me stall it as I don’t over rev bikes on takeoff.

After the 6000 service it did seem a bit better – for a day.

This has given some suggestions to check and I guess I will have to do this myself – would have preferred if a dealer could admit the problem and look at fixing for me as it is new.

Any other suggestions would be appreciated, not sure what the wife will do when she sees me pulling apart my 12 month old bike - think there might be a little "discussion" at the time.