Cold Stumble

[ReserveBum]

unless i let her warm up for @ 8 min or more.....she stumbles out of the driveway and up the street. Always done that, since new. Even happens if you go somewhere and shut her down for an hour or so, still have to let her warm up or.....You are going to be "That Guy". Mentioned it to dealer and all I got is " there is no issue, you just have to feather the clutch".
Funny you mention it but I do not recall the issue happening in Colorado.....but I did get a tankfull where I got 50mpg!

[2wheelsforme]

I have never had a stumble at all but I did appear to get really good gas mileage while in Colorado. I asked a local to high altitude and He said no it was just because I was riding slower. Once got 265 on a tank. Back to sea level and 220 miles tanks have returned. I think either the altitude or the type gas may be the reason.

[3Chief]

I have never had a stumble at all but I did appear to get really good gas mileage while in Colorado. I asked a local to high altitude and He said no it was just because I was riding slower. Once got 265 on a tank. Back to sea level and 220 miles tanks have returned. I think either the altitude or the type gas may be the reason.

+1, gas mileage is back down to normal.

[GaTeach]

I don't remember, did I stumble walking away from the Taco Bell in Cherokee ???

Wait, was that you in the bed of that pickup ordering nachos grande with extra quacamole?

[GaTeach]

Isleen grew into the cold stumble after ~20k miles.
I've always used 87, per the owner's manual.
I'm trying 92/93 now and I'll see if that makes a difference.
Cheers,
Steve

Shooter has convinced me to try the 93. Yesterday was my first tank. AND I filled up before the orange light came on. I’m quite proud of myself.

[2wheelsforme]

I don't see how a higher octane will help with a stumble. Octane is a measurement of a gasolines resistance to knock. I think what we call marine gas or pure gas instead of that 10% crap might help.

[53driver]

I've had the 92/93 in for two tankfuls now....no help with the stumble.
I'll try the "no-ethanol" solution next tank.....
Cheers,
Steve

[53driver]

Shooter has convinced me to try the 93. Yesterday was my first tank. AND I filled up before the orange light came on. I’m quite proud of myself.

That fuel pump will last forever with attention like that!

[tenxxx]

The lower octane has a lower flash temp. Dip your finger in it and blow,, gone like alcohol.
!0% ethanol lowers it even more. It burns very fast and a hot spark plug tip can ignite it before the spark gets there.[spark nock]
High octane= slower burn.
High octane higher flash temp. Burns longer and through out the power stroke.
Slower burn = more consistent, efficient flame. The hotter the spark the better the burn.
With high octane gas you can open the spark plug gap to max setting, if yer gonna run it all the time.
But what effect it has on the stumble is a good?

[53driver]

The cold stumble is definitely not a pinging or knocking issue.
It is a fuel to air ratio issue generated by the ECM when it gets input from the sensors that the fuel map then translates to a mix that is "not exactly correct" for the current conditions.
Is it the sensors providing false info?
Is it the ECM going wonky?
Is the fuel mapping artificially leaned out for EPA regulations?
Will non-ethanol make a difference given these variables?
If so, how?
Too many questions....time for a Makers Mark.
Cheers,
Steve