First Log Stock MS6 - high KR?

[Fstrnyou]

I occasionally get a rather large stutter but hadn't felt it in quite a while. Installed VT yesterday evening and did some driving last night and today to get the fuel trims settled. Came across a good stretch of straight and flat road and did a 4th gear log for the first time. Low and behold, I caught the stutter/hesitation in the log. On the way home, I look over to the KR field and see nearly 6KR max!!! Got home, opened up the log and BAM, the insane KR is where I feel the hesitation. WTF is happening? Car is stock with exception of a new CS BPV, but this exact hesitation has been happening for quite a while, like I said earlier. Fuel rail pressure is all over the place, but always above 1600.

The only thing I see relating to the KR is that the AFR's might not have come down fast enough after peak load, but once KR hit, the AFR dropped quickly.

And for the hell of it, added VD of the log.

[sheston]

Looks like you had one big KR event, and it's just decaying the rest of the time. If you are going to self tune, I would decrease the decay value so you can see separate events. Also, you need to log several other parameters, throttle position (to see if the throttle is being closed by the ECU), Ignition advance (to see how the ECU is controlling timing), and various others that you can find in logging threads.

As far as this log, did you hit anything in the road? hear any noises from the engine suspension? If you log more, see if the KR happens as the same rpm, etc. I can't really see anything in the log that would explain the KR. Add some of the other parameters and try logging again.

As far as helping your engine (I assume you don't know how it was taken care of), I would change your plugs, gap them to 0.026 or so, stretch your ignition coils, change your oil and the other maintenance stuff. Good Luck

[DingoDave]

I would also do a compression check when you change your plugs. You can rent one at Autozone/Oreilly's. Check for anything loose or unbolted that could be banging against the engine.

[Fstrnyou]

Replaced plugs with OE back in Feb maybe. Gapped to .030. Springs are stretched. Regularly change oil. Air filter good. MAF sensor clean. Did a coolant flush. JBR boost tubes and recirc hose. Replaced original BPV w/ CS BPV a few days ago, but first noticed this exact event about 6 or so months ago, so I'm ruling that out. From what I can recall, it's always around the same RPM, 2700-2800.

As for the log, I just picked general parameters for curiosity sake for my first log but had no expectations of capturing the knock event as it hadn't happened like that for about 2 months. Even after repeated attempts to replicate it. Sometimes it's a barely noticeable stumble and other times I feel no stumble at all. There will certainly be more logs, but it could be a month before it happens again and there's no guarantee I'll be logging at the time. What PID's should I drop? I don't want to log too many and sacrifice resolution.

On a side note, what's up with those BAT's? 140's while cruising and the BAT's drop drastically under boost until it can't keep up with the hair dryer and it climbs back up. Ambient temps were around 85F.

Originally Posted by DingoDave I would also do a compression check when you change your plugs. You can rent one at Autozone/Oreilly's. Check for anything loose or unbolted that could be banging against the engine.

Did a compression check a few months ago. If I recall correctly, they were 180, 180, 180, 185.

[r3d]

Prob need to get your injectors cleaned, at that mileage they are caked.

[Fstrnyou]

Good call. I'll scope out an injector set from a part-out and have them cleaned so I'm not immobilized for a week or so.
It was also suggested that a new O2 might be a good idea.

As sheston stated above, I don't know the history of this car. It had 115k miles when I got my hands on it. I've fixed/replaced/checked a lot of things but still have much more to do.

I don't intend to tune for performance/power until this engine is back in tip-top. Aside from a rebuild...

[sheston]

I would think at that mileage your valves and pistons are the things that would be caked. The EGR totally ruins these cars if your not spraying Meth to keep things clean. You might think about looking at those

[Fstrnyou]

I have an EGR delete kit on my kitchen table. OCC kit to follow. And I would like to add a water/meth kit primarily for cleaning purposes as I don't intend to go past about 350whp. I don't have the money or resources for an engine rebuild...right now.

[djern]

you have plenty of nator at your disposal in charlotte time to meet them guys bro..we can get ur car straightened out!

[Fstrnyou]

What's up Ern? I knew you'd find me eventually.

I occasionally check for updates on the next cars and coffee, or was it mugs n mufflers? Beer n boost? Tea n turbochargers? Eh whatever.

I'm way down in Rock Hill. Seen a few MS3's in the area. Heading up your way, I'm limited to weekend trips and I have my daughter half of those weekends. You won't want me around if I have her. Lol. She's 3.

[Pu Manchu]

Originally Posted by Fstrnyou You won't want me around if I have her. Lol. She's 3.

or maybe he will.

[Fstrnyou]

Hmm..
/Google search "sketchy gun shop with no background check"
Click - buy now.

Okay, I'm ready.

[Fstrnyou]

Two more logs in the books but still haven't been able to capture the big KR like the first log. It has done it again, but not while logging. oh well.

2nd log - added the stock TMIC shroud. Thanks @HaXiR; Made little more power from the lower BATs.
3rd log - short 4th gear run on the interstate (4200-5700). leaned out the WOT target AFR's to 0.8 lambda up to 5.5k, 0.75 @ 6k, 0.7 after that. I don't think I've ever ran it to 6k before. Obviously, running leaner made more power. Got a few ticks of 0.7 KR up top.