FR-S cold start stumble - video
 

My FR-S startup on a cold morning. Anyone else experience something like this?

[ame="https://www.youtube.com/watch?v=Ky_vDK4ePHI"]FR-S cold start - YouTube[/ame]


It sounds like a "knock", followed by a drop in RPM's. It feels like something is stuck and becomes unstuck. It only happens at startup after the car has been sitting for a longish time. Otherwise, the car runs like a champ.

This was the worst occurrence and I was just lucky (unlucky?) to be recording on that day. It seems to be temperature related. Although, today we were in the 40s and I got a single milder "knock" in the morning and then after work..

Brought it to the dealer, they gave me an excuse about not being able to reproduce it after four days in the shop and supposedly they sent the video to Toyota.

Plugs? Winter blend fuel? Belt? Alternator? Oil?
What the hell could it be?

the cold delays the startup sometimes but that knock isn't normal IMO.

Sounds like popping in the exhaust from being really rich on a cold start. Mine does it sometimes when it is really cold. Have you listened to it from the tailpipes when it does this?

Thanks guys.
Nope, I didn't even think to listen to the exhaust. I know what I'll be doing tomorrow morning, haha.

Seems to me if it was something really bad it would throw a cel and ur check engine light would come on

Mine was doing the exact same thing as the video during the coldest mornings this winter (in Toronto). Maybe about a dozen of my start-ups sounded like that. Haven't heard it since the weather got a bit warmer. I changed out my stock exhaust to TRD cat-back a couple weeks back, but am pretty sure I heard the same sound at least once since then.
Not sure what it could be.

I started noticing this on a few of my start ups as well. I think so far it's only in the morning s when it's cold.

I've been experiencing this strange popping on and off for more than a couple of months now...
Here's another video, first it completely fails to start and then you can hear a faint pop at 7 sec. Note the temperature guage...

The dealer doesn't want to do anything until they can reproduce the issue themselves which quite frankly is starting to piss me off..

[ame="http://www.youtube.com/watch?v=1-M3fM-G6k4"]FR-S startup stumble - YouTube[/ame]

How long is longish? You could just go to the dealer and chill there for a while and show them yourself. Does this happen often?

Damn, i think my BRZ just did this when I started car after parked all day at work. Heard 2 sounds like it, but wasn't looking at tach, since today was the first time I noticed it. Why now, after 8,700 miles?
It's been colder the last few months than today...

I've seen the problem on my Supra, when moisture condenses within the intake, exhaust and pretty much the whole line... as said, it's primarily on cold mornings after sitting for a night cooling down, and as the temperature increases condensation occurs within the cold parts.

curious what exhaust?