Occasional misfire and Clacking/clicking sound.
 

So, I just purchased a turboed 2013 FR-S with 80k miles. I've noticed on cold-starts and at idle an occasional misfire. It happens once and only once around every 1.5-2 minutes. I also started hearing what seems like a clacking/ticking/clicking sound coming from a cylinder after it idles down . (On cold start idles around 2500 then calms to 950 after about a minute, not sure if this is stock, or a tuning thing). While messing around with me P3 gauge, and clearing the codes (there were none stored or active before I did this), I noticed the sound go away and then come back 30 seconds later. As you can probably tell, I don't know a ton about this car, especially with the aftermarket turbo kit (Avo turbo kit). I do know it's limited to about 8 psi of boost at max, and that its fun to drive. Any suggestions on what this could be? I'm thinking maybe a fuel injector going bad? I do also know the valve spring recall hasn't been performed yet, could it be an indicator of a spring going bad? Tomorrow morning I will take a video and post the sound, if I can post videos, I'm also fairly new to this forum.

Welcome! A sound clip makes all the difference for these discussions. Is it an automatic? Don't worry. We may tease but it's all in fun. They're great.

It's a 6 speed manual

Then we can rule out the vacuum pump.

how is the misfire count when it happens on log?

I've think I've figured it out. It appears to be the high pressure fuel pump noise that is common on these cars? I will still post a video of the sound in just a minute, but from the videos I've heard of this noise, this is what it seems to be.

Well, it might not be the hpfp after all. There is a faint chirping, but more of a ticking. https://www.youtube.com/watch?v=F2kGX4X_Aw0

Not sure if it's from YouTube, but the sound isn't as deep, its more ticking then clacking, if that makes sense. It does kind of sound like lifter tick, but as I said, it's not constant, which leads me to believe this isn't lifter tick.

From a warm start, after a few seconds you can expect it to switch over from PI to DI. Once recognized, the sound is obvious.

edit: whoop. Just saw your vid. Yes, that's DI in action. Normal.

Sheesh, so if that's normal, is there any way to quiet it down? Or just live with it?

lolol...

https://i.gifer.com/5dwG.gif


I think it's a matter of perspective. My wife's C300 is only a little bit quieter because it's stuffed with gobs of fiberglass, or whatever. As long as I know what it is, I'm fine with it. Makes it unique.

Okay thanks, and random question, how do you do that like "Thank You" thing? I can't find the button for it or how it's done,

I believe it appears after your 10th post.
Which you just did.