I have a 00 EGC, put gear drive cams, PC III and true duel exhaust on the bike in Jan 08, it started and ran great all year (10,000 miles) about 2 months ago on initial start up it starts right up goes to the cold idle rpm for about 1 second and them drops to about 500 rpm and spits and sputters and will not stay running unless I goose the throttle lighly once or twice then it will go to the cold idle rpm of about 1500 and idle down like normal. I un plugged the PC and started the bike with the stock cmputer and it does the same this, I have metered all the sensors and even changed the air intake sensor with no change in the running of the bike on initial cold start up. Temp here in VA has been very cold but the bike sits in a heated garage with an everage temp of about 60 degrees. Any help would be great.

 

I would look at the idle speed motor. See if it is closing the throttle completely and not holding it just off the throttle stop. Also vacuum leaks and other components on the intake.

 

FXSTDSE2

Thanks for the repsonse, I will give your thoughts a look over tonight, thanks for your time. Is that motor also called a stepper motor? It does move when I turn the ignition swith on but will look at it more closely. I did put new intake gaskets/rubbers on after I changed the intake temp sensor, but will give the intake a complete look over tonight also, I will let you know what I find.

 

Yes, If you want to call it a stepper motor. Sometimes it can actuate but once it touched the lever it wont move it. Hence, start stall. But knowing you have had the intake off, everything should be checked closely. If you are familiar with FI, the MM EFI is a pretty simple system just improperly diagnosed at times and then becomes a headache and expensive if you replace 3 parts that were not bad.

 

Do an unlit propane torch intake vacuum leak test as well. Do both cold and after the engine warms up.

 

Try cleaning the throttle body with a spray cleaner. Put the straw of the cleaner in to the two holes at the top of the throat and clean them out. They will get a little gummy and they supply the idle air when the throttle plate is nearly closed.

 

Another thing to consider is the side throttle plate on the MM throttle body. Inside this plate is a miniature bearing that in time starts to get rough, and the idle actuator senses this resistance and will act erratic and idle lower or seemingly lose the cold idle settings. I changed mine out and the idle returned to acting normal immediately. The bearing is cheap and easy to replace. The outside plate fits under the idle stepper motor rod and moves the throttle shaft for the cold idle.

 

Couldn't get to the bike last night, I'm gonna hit it right after work today. Thanks for all the great input, I hope to have good news for all this weekend. Thanks.

 

Tried to clean the throttle body this weekend with carb cleaner like ajayrk suggested, no luck still doing the same thing, tonight I'm going to take a real close look at the idle control motor.