Ok guys,I got a question.When my 98 Rk hasn't warmed up totally and I head down the road,it wants to "sputter a little every time I shift gears.You know,like a bit of hesitation or short dead spot,similar to what a carbed bike would do if it were a tad cold and didn't have the choke set just right.It only does it when the motor is just still a bit cold.I can go down the road a mile or so,stop and take off again and it's fine. It's been this way for awhile and it's really no big deal just more of an annoyance.If I let it sit there and warm up good it's fine.Just seems to me that a fuely motor shouldn't do this at all.?? Now granted I do try to let this Evo warm up,especially in cooler weather but the fuel injection shouldn't really have a slight dead spot regardless if it's cold or totally warmed up. What do ya think??

 

Have someone follow you and see if it is burning black when doing it, MM efi will load the cylinders cold and flutter while riding until it leaves the cold start mode, if it is lean, it should spit out the intake on a quick blip. If it is staying in cold mode longer or releasing it early, the engine temperature sensor could failing and won't always send a code.

If your idle stepper motor is set proper, it will still be on a slight higher idle before being released by the ecm and dictate if in cold mode.

Let it warm up and stay within the MM's design, were talking early EFI my friend, if it acts up after warming up let me know.

 

Thanks buddy,I appreciate your response.Naw,it doesn't do it after fully warming up,just when it's a little cold. Like I said ,I usually try to let it warm up good before hitting anything close to cruising speed as alot of guys before have told me ,Evos can be prone to gaskets leaking if ya start running em fairly hard on a cold motor.

 

I am not an expert on your MM EFI, but, problems such as you describe could be caused by a defective cylinder head temp sensor.

 

Yeah Doc,that's prob. the culprit.....seems like it's done this for quite some time and as long as it doesn't get any worse or do it at all when it's good and warm,I'll let it be....don't feel like pulling the front rocker box off again till i have to!

 

You do not pull the rocker box to change the temp sensor. Do not wait too long to swap it out, it's ugly when they get worse.

 

Fuel injection, "mutter, grumble, pah!"...work of Satan I tell ya!!! I don't work on EFI bikes unless its mechanical....too old and daft to learn all about codes and sensors....makes me sweat just thinking about it but its good to see there are some knowledgable types on this forum!

 

Get yourself a long drink and take a seat over here - 1997bagger knows his EFI stuff!

 

Been a long time since I had a beer in Bedfordshire! About 9 years now

 

I can't think of much that has changed, so hopefully you should recognise most of it. The trees are just flowering and greening up now, so the place is almost at its seasonal best!