mtnman82

My car has felt doggish lately and I'm not getting the kick from the K27 like I usually do (the on/off kick when the boost kicks in). I've done a bunch of checking for vacuum leaks to no avail. I'm attaching a screen shot from a 4th gear pull last night. AFR goes to 11.5, 14.7 psi at ~3K rpm. It does seem to run a bit erratic, not as smooth as it usually is, too. Am I just imagining things? Or can someone smarter than I deduce something from the log?

mtnman82

No comments on this? Could the 'erraticness' be something bad in the wiring? Or wastegate? Any suggestions where to look? I can definitely feel it in the car. Also still seems like boost is building slower than it should...

refresh951

AFR looks strange. You hit AFR floor way early. Nice that AFR is 11.5 (a bit rich but safe) but it is getting there very early and almost looks too flat. You should hit an AFR of about 13 at 2-3 psi of boost once out of closed loop. You are running way rich during spool up if the log is accurate and thus exhaust temps are down resulting is slower spool.

mtnman82

That's exactly what the car feels like. Plus I can feel the 'erratic-ness' you see. Any ideas? Small or weird boost leak?

refresh951

can you email me the log file? shawn@refreshsupport.com

Tom M'Guinn

That AFR line does look too flat to believe, and before it flattens out it seems to be moving around oddly when nothing else seems to warrant it. Have any more logs to see if that was a fluke? Have you checked your grounds recently?

Stab in the dark (and unrelated to the AFR curve), but did you test the bypass (blow-off) valve when you were checking the vacuum lines to make sure it's closing and opening smoothly?

mtnman82

Thanks for your time Shawn and Tom - I DO appreciate it!!!

Sent you a couple log files Shawn.

I'll check the BOV Tom, no I haven't checked it in a while.

Thanks for the help guys!

User 52121

I was thinking the same thing.

Or, rather, I was thinking, "Hey wow that AFR is super flat, WAY flatter than mine ever looks... I wonder if something is wrong with mine?"

Wish I had something to offer ya but you've already got Shawn on the case, he's spent more time in TunerPro than I have.

Paulyy

o2 sensor possibly. if the DME thinks it's in closed loop, it'll run rich always.

User 52121

What size is the turbine wheel? Looking at logs on my car (T04E w/-8 hotside) I hit 14psi around 3400. If you're getting there at 2960 then it sure seems to me like you're already spooling up pretty quickly. Paulyy might have a point - though do you see regular O2 cycling in the logs at part throttle?

refresh951

I looked at the logs. Clearly something wrong with the wideband data. It is not accurate. Log files show increasing idc but AFR hits a floor of 11.5 and never goes lower. Need to get that sorted. I am guessing it is the wideband 02 sensor. I think you are running pretty rich but hard to say until you get the wideband fixed.

mtnman82

Thanks for looking at the data Shawn!

I do see oscillating in the afr when idling, 14.5~14.7. I'm using the stock narrowband for the computer, a fairly new unit (one of the universal 4-wire ones).

This data is from a Zeitronix, ZT-2, an older unit. Could it be something in the settings somewhere? Guess I'll need to get a new wideband sensor to make sure that's not the culprit... Does (should) it need to be a Zeitronix wideband sensor or is there a better place to get one?

refresh951

You can get a Bosch O2 sensor from Zeitronix for $79. It is plug and play.

http://www.zeitronix.com/order/order.htm

Tom M'Guinn

Zeitronix is pretty responsive to emails. You might send them an note and tell them what you are seeing in case they have any insight on which part is the culprit. When the sensor signal is disconnected, mine defaults to a fixed 14.7. I reseated all my connectors, cleaned the pins, and resoldered the main connectors on the Zt-2 board, and that seemed to fix it. In the past, when wideband sensors started to go out, I've seen them get slow/sluggish, but never stop at a particular AFR. Maybe I just changed mine out before they got to that point though? If you want to try a slightly old/sluggish sensor, just let me know...

mtnman82

It's on it's way. Hope it comes quicker than the ZR-2 I ordered a month ago does (which just arrived today)...

Omni - I have no idea what's on the inside of the turbo, but it is a K27/6 on the outside. It's an old school Powerhaus from when a previous owner lived there in AZ. According to the receipt it's was their K27DR quickspool and I've verified the /6 housing.

Thanks for the offer Tom!