6th Gen Idle issues after a short ride

I have a 4 mile commute to work. On colder mornings, when I arrive, the bike doesn't want to idle and will stall once I've come to a stop. Popping it into neutral and getting the RPMS up high usually prevents it from stalling if I catch it in time? Is it just a temp, short ride issue? Doesn't happen when I ride longer or in the afternoon?

 

Presuming the air filter is clean and that there is no FI light on, a couple of things an owner can readily check are for any cracked or loose vacuum hoses. Unfortunately that means removing not only the air filter lid, but also the base. Be sure to look closely at the hose going to the fuel pressure regulator. That can cause all sorts of confounding problems though probably not this issue. While that's off, you can also check the coolant temp sensor, which if faulty, could be telling the ECU that the engine's "warm" when it actually is not and thus the ECU sends commands for a "warm" engine instead of a "cold" one. Then once the engine actually is warm, the commands are then the correct ones and your idling issue disappears. A bad ECT should set a code (7 blinks), but maybe not - it may be in the process of failing but has not yet completely. Remove the connector (it s/b on the back of the front head), and be sure that the resistance across the sensor is 2.3 to 2.6 ohms at room temperature (engine cold). Turn the key on and be sure that you're getting the proper reference voltage at the connector, 5V, across the yellow/blue wire to ground. If that's good, check for 5V from the same yellow/blue wire on the connector to the Green/Orange wire on the connector. If those read differently, it's a good idea to check the wiring harness for chafing, cracks or loose/broken connectors and also chassis grounds for corrosion. If it's an '02-'05 and the wiring recall has not been performed, it might be a good time for it. The main battery ground to the chassis is under the tank at the back and that's always good to check. If the voltage is good through both, just be sure the connector is seated securely to the ECT. If that all checks out and your base idle when warm is at spec, may want to reference the shop manual (can be downloaded if you don't have a paper copy) for add'l diagnosis. Best of luck.

 

Check your throttle for excessive slack, adjust idle speed (knob is located above oil fill point, right side) after engine has warmed up, should be ~900-1000 (check manual for that). Check air filter, make sure you dont have a mouse nest in there.

 

6th gen idle is supposed to be 1200 RPM +-100. I have problems with random stalls at 1300 and find that 1350-1400 is better.

 

The pre 2006 model idle was set at 900 to 1000 rpm. The later models after the VTEC engagement change to 6400 rpm have a higher idle at about 1300. I learned this when I went from a 2005 to a 2007.

 

is your bike starting on the high idle circuit when its in the 50s or colder?
i only have these problems on mine when its a little cold outside, but not quite cold enough for the wax unit to use the cold idle circuit.
see if bumping up the idle a tad helps...

 

Thanks...no, the idle problem doesn't seem to be an issue when the bike is running on really cold mornings (Sept Oct) Probably low 60's. I haven't checked to see if the air filter has been changed since I bought the bike with 30K Km on it...so that might also be a stop gap?

 

did you figure out the problem?

 

Thanks for all the suggestions. When I changed the plugs last week, I replaced the air filter. It obviously hadn't been changed since the bike was purchased. Cleaned the filter, changed the plugs and the bike runs like a swiss watch! Ya...air restriction can make a difference in the idle!