Thread: Quirky turbo issues

all i saw was some crap about a afc neo when i read it.. but with a wall of text ya cant blame me for skimming a little.. i've never used a aem wideband so wouldn't know about that test, still seems like a shitty way to test if ya ask me..

even after i re-read it, it seemed like he was talking about one of those narrowband gauges, that read only rich/stoich/lean..

if dude woulda been like hey man reread my first post i mentioned a wideband and left it at that, i'd have apologized right away, but instead he got mouthy.

any how no bigs, i unsubscribed from the thread, only posting again to reply to you lol

It's true, I could of been maybe a little more descriptive. I just felt the aggressive tone, so I responded and provided the information you sought with a photograph. I was a little over the top myself in response. Could have been more patient.

it really could be a massive leak in the BOV under vac

I will be taking a look tonight. And feel if there is leaks. I will take a video and get back to you guys tonight or tomorrow.

Okay, here is a short clip of what is going on. The runs just reads lean unless I'm throttling like crazy, my pyro looks like is hot, it's on the header. And vacuum is negative 14.

I re-routed the intake vacuum to atmosphere currently to check I the turbo would stop blowing oil (which is stopped) I plan on getting a good baffled catch can and routing both to the intake. Maybe have the T off the valve cover and the hose off the throttle body go into the catch can and reduce to a single. Any thoughts on good cans?

There is no leak from the blow off valve. It doesn't move at all them throttling at idle which I believe is normal no serious load on the motor.

Is that compressor stall? Doesn't sound as violant as surge.

The check engine light turns on at low revs but goes away at high revs and comes back on at low idle, the car will not idle without stalling.

Sorry about the poor video equality

What code comes up?

A) It sounds very much like a MAF. How did you go about checking it? Did you do it per FSM by checking voltage?? Typically several signs present themselves when the MAF has somehow been removed from the Loop

1) Not able to rev above 3,000 rpms
2) Inability to idle (immediate lean condition)
3) Immediate (off the charts) lean condition both when you get off the throttle and during idle (which, since as far as the ecu is concerned, no MAF signal = no air = no fuel compensation)

Grab the FSM (and make sure it's the correct MAF you are referencing as per guide as, although similar, different MAFs have different calibration test parameters) and the MAF guide through JWT and go over BOTH the MAF wiring and MAF sensor itself to confirm.

B) Compressor stalling, not a big deal if no load is on the engine. But if you have a BOV, your BOV may not be operating correctly. Easy way to check (since you are open atmosphere) is to simply rev the engine quickly and place your hand over the BOV to see if it vents. It looks like a Greddy, so spring pressure should be adjustable.

C) 14 in.Hg sounds a little high (or low depending on how you look at it) side for idle. Stock cammed cars should be seeing 20+in.Hg at idle. S4s (and BC stage 2s) between 20 and 17in.Hg. Sounds like a vacuum leak (which could be your BOV or how you have your vacuum routing)

Goodluck!

As mentioned before, incorrect,. Almost all current day "high" quality widebands instruct you that this is a good way to test and check calibration of a wideband. If you did not "initially" check for calibration of your wideband in this manner, it could very well be off (I personally checked calibration curves of my NIB LM1 and MTX-L in this manner, before recalibrating in car to make sure the wideband was reading correctly)

Thanks for your input!

If anyone has any ideas let me know.

I'm pretty sure my TPS is spot on I replaced it last year.

And the o2 is new.

Would unplugging the o2 help you think? Maybe it's shooting a code because the o2 see's it lean. If I were to unplug the o2 at idle maybe this would remove the check engine light ( FOR DIANOSIS ONLY) not as a permanent fix.

I still have to have a buddy come over with his snap on scan tools run the code this weekend