Idle Surging again

Busa45

Registered
I have an 02 Busa with about 25K miles. About 10 months ago I had a idle surging problem, bike would get a mind of it's own, idle would surge up to about 1800 and then back down, come and go. I had sourced it to a bad Inlet Air Temp sensor (or so I thought). Replaced it and the bike ran better than ever.

Last month, it started doing the same thing again. I checked the IAT sensor, even replaced it with a resistor to see if it had gone bad again but bike still had the problem. Usually happens after the bike has come up to temp. I have checked engine temp sensor, air press sensor, gear position switch, stator resistance, inlet air valve in air box, a few other sensors (I don't recall now), checked all the vacuum hoses / connections, used injector cleaner in the fuel tank and cleaned the throttle bodies. My model has no O2 sensor so that's not it.

Still no luck. I must be missing something really simple. Getting ready to take it to the local shop.

Did I miss something???

Thanks.
 
I had something similar on my BMW bike and it was a problem with the throttle body butterfly busing being wornm and allowed air to bypass causing fluctuation in idle. It creeps up just like you described. I'd suggest looking for a vaccuum / air leak. Wardie:banghead:
 
Took the bike in and got a call from my local shop. They said all they could find was some corrosion in the plug caps and the bike runs okay now. Anybody heard of such??? I change my plugs every 7500 miles (2500 on this set now) and the caps are pretty tight. Don't remember seeing anything in them.

Any thoughts???
 
I have never heard of corrosion in the plug caps.
They have a rubber seal all the way around them, so I don't see how water or anything else could get in there?
They make a di-electric grease for plug caps, that may help them seal and stop corrosion.
I use it because I always have and it makes removal a bit easier.

I don't know how that would cause the problem you stated?
 
Back
Top