Not hitting boost targets, not boost leak

[ADHDAdditiv]

Ok so, I do have another thread up, but its pretty dead. So a while ago I started having this problem where i couldnt hit the stage 1+ boost targets (Cobb accessport). I have a ton of knock on top of this.
I've been trying quite a few things, including trying to see what WOT would do when the car is half warmed up (I know this isnt a good thing), the car has no knock at all, but still not hitting the boost targets, as soon as it gets up to temp, knock comes back.
Also a few days ago, the car decided to work flawlessly for 2 full days. No knock, 15.5psi, spooling fast, absolutely perfect. I filled it up with gas, runs like shit again. A long while back, I accidentally filled up at a station who had some bad gas. I ran around with it, didnt boost a whole lot while i had the shit gas, then filled up at a station I knew was good. I dont remember if the problem started then, but I have a feeling it might have.

I have already checked for boost leaks, doesnt have any.

So basically, car ran like shit, worked flawlessly for a couple days, filled with gas, runs like shit again.

Here are some datalogs to look at, taken about a week apart, weather was about the same. One is while it was running like shit the other is when its running perfectly. I'm totally stumped as to what this problem could be, really need help.

[[R]usty]

Mods?

[ADHDAdditiv]

Woops, sorry.
Corksport Sri stage 1, Cobb accessport running stage 1+, drilled out second cat.

[speed23]

Knock sensor doesnt turn on until the coolant is up to temp, so you were getting knock. But you didnt know it

[ADHDAdditiv]

Originally Posted by speed23 Knock sensor doesnt turn on until the coolant is up to temp, so you were getting knock. But you didnt know it

Good to know, thanks! Actually rules out some of the things I thought it might be.

I just went down to the store and got some nice fuel system cleaner.

[ADHDAdditiv]

Ok so my car decided to behave pretty much perfect (little bit of knock here and there, but I wasnt complaining). At least most of the time. here are some datalogs I took, all within 20 minutes of eachother, "Just after low boost" and "low boost" were taken literally on the same road, I did a pull, turned around and went back.

I'm not the best at reading MAPs ATM so if someone with more experience could look at these and give me their thoughts, I would greatly appreciate it.

[ADHDAdditiv]

Bumping again because there is a drag day on friday and I'd like to actually race in it.

I was driving yesterday, did a pull, and it did the most peculiar thing, which might give everyone a clue to what the problem is.

I started out with the usual problem, (4th gear pull) slow boost build (took 200rpm to get to 11psi)m then at about 4.3k rpm it seemed to jack into high gear and hit 15.5 psi (which should be the stage 1+ boost target) and had 0 knock. It felt like a random kick-in, like it just sort of started working. I continued into 5th gear (shifted at 5.3k) and after about 2-300 rpm it went back to hitting 13.5 psi and knocking again.

Im seriously stumped on what the problem is, considering how random it is. Please help!

[Vansquish]

It looks like your car is compensating for IAT and BAT by dropping WGDC levels. If you look at the RPM ranges on the logs where you're knocking, and compare it with the same area in the logs where you're not knocking, you can see that in the non-knocking logs, you've got: more airflow (approx. 25 g/s higher @ 4K rpm); higher WGDC levels, and significantly lower IAT/BAT.

To me, that says there's a compensation table kicking in to prevent your motor from blowing. The answer, I believe, is go VIP, read the tuning materials there, and try yourself, or better still, get yourself a custom tune from one of the e-tuners on here.

[ADHDAdditiv]

Originally Posted by Vansquish It looks like your car is compensating for IAT and BAT by dropping WGDC levels. If you look at the RPM ranges on the logs where you're knocking, and compare it with the same area in the logs where you're not knocking, you can see that in the non-knocking logs, you've got: more airflow (approx. 25 g/s higher @ 4K rpm); higher WGDC levels, and significantly lower IAT/BAT. To me, that says there's a compensation table kicking in to prevent your motor from blowing. The answer, I believe, is go VIP, read the tuning materials there, and try yourself, or better still, get yourself a custom tune from one of the e-tuners on here.

Thanks for the reply. Makes sense why its doing causing the low boost and knock but I'm wondering why it has to do that in the first place. The Cobb tune shouldn't be that bad out of the box.
Do you thinks its all tune problems or could something with the engine be causing it?

PS any spelling or extra word is because I'm on my phone

[btstarcher]

How many times have you filled up since putting the shitty gas in? And what do you mean by "bad gas?" Did you use 87 octane?

[ADHDAdditiv]

I got the bad gas like 3 months ago so like 12+ fills. And by bad gas I mean it was after winter and I guess either some settlement or water or something got into their 94 octane tank. My dad had problems after filling there too

[btstarcher]

That happened to me a couple summers ago; it took a long time to get back to normal. I'm not sure why. I drive around 5k miles per month and it was better after a couple months. Then my engine blew LOL

[ADHDAdditiv]

Originally Posted by btstarcher That happened to me a couple summers ago; it took a long time to get back to normal. I'm not sure why. I drive around 5k miles per month and it was better after a couple months. Then my engine blew LOL

O.o
Should I be worried?

[btstarcher]

Well it depends; I don't know if all that knock/detonation I had with the bad gas contributed to the premature failure or not. It may have weakened the rods over time.


But it was probably more to do with my dumb ass learning how to tune with e85 mixes and advancing the timing past the point of no return.

[ADHDAdditiv]

Ah OK. So basically run some fuel system cleaner and wait it out?

[btstarcher]

No, that shit made it worse. Avoid WOT and drive to almost empty, then refill with good gas; if you have e85 maybe a gallon or 2 of that also. Just keep running good gas until it's back to normal. Might also try that Heet stuff, something that will eliminate the moisture in your tank (if there is any).

[ADHDAdditiv]

Ok. I've already done that, should I keep doing it til it runs good?

[btstarcher]

Oh, yeah.....check your plugs, mine were ruined.

[ADHDAdditiv]

Originally Posted by btstarcher Oh, yeah.....check your plugs, mine were ruined.

Will do. What about my injectors and fuel filter?

[btstarcher]

I didn't see that much KR in your logs. It rarely was over 1 degree.

Unless you want to pull everything off to get to your injectors and send them to get cleaned, I'd leave them alone. I've never touched the fuel filter and I'm at 235k miles.

[ADHDAdditiv]

Originally Posted by btstarcher I didn't see that much KR in your logs. It rarely was over 1 degree. Unless you want to pull everything off to get to your injectors and send them to get cleaned, I'd leave them alone. I've never touched the fuel filter and I'm at 235k miles.

You must have looked at the wrong one lol. But OK. I'll check the spark plugs tomorrow and recap if needed. Thanks for the help. If anyone thinks it could be something else let me know. I will post the results tomorrow.

[blackmicamps6]

i had bad gas and my plugs were bad.. then i added octane booster (stupid i know now) and they were fucked. check your plugs run that bitch out till way below the E and fill up at the last second.

[Vansquish]

Originally Posted by blackmicamps6 i had bad gas and my plugs were bad.. then i added octane booster (stupid i know now) and they were fucked. check your plugs run that bitch out till way below the E and fill up at the last second.

That's not the best plan either...it's a good way to suck sedimentary crud that might not normally get sucked into the fuel filter into the fuel filter.

[blackmicamps6]

Originally Posted by Vansquish That's not the best plan either...it's a good way to suck sedimentary crud that might not normally get sucked into the fuel filter into the fuel filter.

never thought about it that way, all i know is that i had to run mine down tot he way minimum to get that bp shit out of my tank and that + new plugs helped a ton

[ADHDAdditiv]

So if I have to get new plugs, which ones do I get. I know there is a list, and I read it (I dont totally understand it though), but for my setup which plugs should I get? I dont really plan on going much further yet due to lower finances.

[chaser27]

Check to make sure your plugs aren't fouled, covered in oil, etc. Knock can be caused by a lot of different things. And yes the Cobb OTS tune sucks that bad. It's the reason I got into tuning. If you don't feel comfortable doing that yourself, there are a few good tuners on here that can do it via email. It will make your car feel infinitely better.

[anavrinIV]

Originally Posted by ADHDAdditiv So if I have to get new plugs, which ones do I get. I know there is a list, and I read it (I dont totally understand it though), but for my setup which plugs should I get? I dont really plan on going much further yet due to lower finances.

run stock heat range plugs. OEM or Denso ITV 20s or the NGK equivalent (I don't know that part number).

[Bratschist]

Here is my adventure with boost leak.

YouTube Short

YouTube Short

Sent from my keyboard

[ADHDAdditiv]

Woops forgot I put this thread up lol. Other one very active.

I ended up getting 1 range colder NGK's for less money then stock ones. I chose them off the spark plug list here on the forum.

Also thanks for that latest video. I had a thought about my problem on the other thread that could be viable.
The top mount intercooler could have a crack in it that is more present during hotter conditions and at certain RPM's the intercooler itself actually rattles, causing my knock. Its a bit of a long shot, but makes a bit of sense.

BTW I ran the stratified stage 1 tune and I hit 17psi exactly like im supposed to, I actually sometimes overboost a bit to 18psi. Still getting the knock but that kind of shows the wastegate is working.