Slight stumble when cold?

[bradktn]

I've noticed in the morning when I first start my FiST that there is a slight stumble or hesitation for the first minute or so until the engine warms up. I have about 2000 miles on it. It’s no real issue, no codes or anything, but just wanted to make sure this is normal/ok. I din't drive it hard anyway for several miles after starting. I'm running premium, 92 or 93 octane.

 

[alexrex20]

The wavering in the idle rpm isn't really a stumble. It's the computer elevating the rpm a tad to help get everything up to temp. If you're talking about what I think you're talking about. Does the rpm sit at ~1000 or more and fluctuate slightly before settling down around 800?

 

[bradktn]

I don't know; I’ll look for that tomorrow. I normally I start it, let it idle for just a few seconds and drive off. It’s more when I’m first starting down the road. May last 15 seconds or so. I suspect it’s what you are referring to. Thanks!

 

[Truth in Ruin]

I’ve never experienced that. I wait for my RPMs to kick down to 750 RPMs before driving after a cold start. Then when I drive off, I drive like a “grandpa” for the first few minutes.

 

[cxwrench]

Mine does that, basically the first time I drive off in first unless it's completely warm for whatever reason. I'll start it, wait for 15-30 seconds while I get situated then gently drive away. First gear almost seems slightly limited or choked off, after that first acceleration it's back to normal.

ETA: '14, 30K miles, stock w/ Cobb OTS Stage 1. Ram Air panel filter.

 

[zanethan]

It's normal. Mine does it as well.

 

[Intuit]

Driving off cold, babying the accelerator trying to avoid creating much torque, holding throttle, I've noticed this in a few different vehicles; and they weren't all cars. Due to the direct drive, (no lossy torque converter,) it will likely be far more noticeable on a manual shift.
http://www.autocodes.com/articles/open_close_loop.php

 

[felopr]

mine does it too if the car is cold
my opinion of it is this:
Is that since the wideband is cold, it doesn't "read" and the ecu just uses a default open loop afr value of 15.7ish, look at the afr, you would see it while it is doing it (slightly lean, warmer exhaust gasses) while the wideband heats up and start to read and go to close loop readings, the hesitations goes away and afr is corrected to 14.7 stoic.
If you turn the car off and turn it on not too long since you turn it off (like half hour, something like that), the wideband is still hot and there is not hesitation

 

[tbST14]

Mine does that, basically the first time I drive off in first unless it's completely warm for whatever reason. I'll start it, wait for 15-30 seconds while I get situated then gently drive away. First gear almost seems slightly limited or choked off, after that first acceleration it's back to normal.
.

Mine also stumbles a bit during the first gear or two, after, things even out.