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Old 02-25-2013, 10:47 AM   #101
endrswrd
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Originally Posted by ride5000 View Post
yes, your gauge source is AFTER the throttle plate.
Ah that is true. I was trying to remember which side that line comes from, but it is after the plate. I misunderstood what you were trying to say in your post. Sorry about that!
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Old 02-25-2013, 11:42 AM   #102
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Car is running great and thanks for all the advice. Sorry about hijacking the thread, just kinda got carried away. Also I didn't think I should make a whole new thread for basically the same issue, but I'll make my own next time.
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Old 02-25-2013, 04:55 PM   #103
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Originally Posted by ride5000 View Post
no, not really.

the turbo compressor generates slightly positive pressure before the closed throttle plate. there is almost never a situation in which negative pressure exists there, and if there is, it's very transient.

fwiw

What about when you are at part throttle and the intake is still in vacuum?
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Old 02-25-2013, 05:45 PM   #104
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most likely still going to be pressurized before the butterfly.

spending some time with a VTA BOV, and adjusting the spring preload, can be very educational! i remember the first time i took an entrance ramp at ~4k rpms and small throttle angle--my txs rfl was blowing off the entire time. keep in mind that most VTA BOVs (every one i've seen/used) have no provision for a filter or anything like that, because of that very reason: 99% of the time, the intake tract between compressor and throttle is under positive pressure, so there's no danger of ingesting debris.
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Old 02-25-2013, 05:47 PM   #105
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another thing that was educational was starting the car with no IC connected. a LOT of air gets pumped by the turbo at idle, way more than would find its way through the iacv or around the throttle plate.
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Old 03-04-2013, 11:07 PM   #106
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I reflashed to 93 LWG stage 2 Cobb map and I'm getting -1 and -2 FBKC WOT 3rd and 4th gear. The DAM is at 1 and this is after probably about 20-30 miles after I reflashed from the 91 stage 2 Cobb map. I will post the logs tomorrow also before the reflash my a/f learning 1 and C fluctuate as high as 7 and over time just go back up and down constantly but I know they move around but I feel like this is to much still. Could my knock sensor be going bad? When I was on the 91 map I got a lot less FBKC while cruising around then the 93. I still am unable to find the mechanical relation to the a/f learning 1 and C value.
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Old 03-05-2013, 06:11 AM   #107
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you realize the 93 map is going to prone to knock more, right? otherwise there's no point in having a higher octane map...
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Old 03-05-2013, 07:44 AM   #108
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Yes I realize that but it never knocked before like that.
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Old 03-05-2013, 08:38 AM   #109
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I reflashed to 93 LWG stage 2 Cobb map and I'm getting -1 and -2 FBKC WOT 3rd and 4th gear. The DAM is at 1 and this is after probably about 20-30 miles after I reflashed from the 91 stage 2 Cobb map. I will post the logs tomorrow also before the reflash my a/f learning 1 and C fluctuate as high as 7 and over time just go back up and down constantly but I know they move around but I feel like this is to much still. Could my knock sensor be going bad? When I was on the 91 map I got a lot less FBKC while cruising around then the 93. I still am unable to find the mechanical relation to the a/f learning 1 and C value.
Are you using 93 oct fuel with the 93 oct map? Knock sensors can go bad, but I would not jump on that just yet. The 93 map has more timing, so it is no surprise that you have more FBKC compared to the 91 map. Try the ACN91 map and see what happens with FBKC.

Your AF Learning value is a little too high. Range C mostly covers cruising around town / on the highway. What are the A, B, and D values? High positive values means the ECU is adding fuel because the amount of air actually reaching the cylinders is more than the amount of air the MAF is reading. This usually points to a vacuum leak and range A and B values should be high also. If they are normal then I would start by cleaning your MAF and see if it there is any change to the AF Learning values.
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Old 03-05-2013, 09:04 AM   #110
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Okay I will try that. I'm running 93 oct fuel. All of my a/f learning values are in normal range except 1 & C which move around a lot which I haven't been able to figure out why. I had a intrack track leak test come back good.
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Old 03-07-2013, 10:55 PM   #111
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So today I was going through the gear on a safe road WOT and my friend behind me said that between shifts I'm shooting flames out my exhaust. I don't think I'm suppost to be shooting flames on the 93 stage 2 LWG map. Does this mean I'm running rich? Or is there a serious problem?

Thank you
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Old 03-07-2013, 11:00 PM   #112
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If you are running a bov vented to the atmosphere and a catless downpipe its normal. You will get momentarily rich between shifts.
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Old 03-07-2013, 11:02 PM   #113
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I am running the stock BPV and also I think they said black smoke coming out of the exhaust as well not a lot of smoke though.
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Old 03-07-2013, 11:09 PM   #114
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AF Learning 1 is just the currently applied AF Learning A, B, C, or D value. It is not a seperate parameter, AF Learning A, B, C, and D are the parameters. It is normal for the values to move around. Any value within + / - 5% is just fine.

The flames are extra gas during the shift. It does not necessarily mean that you are running too rich while you are WOT. Our cars do run relatively rich with an OTS map, 10.x AFR, maybe a low 11.x AFR, but sometimes even a high 9.x AFR for a brief period when the turbo spools. The black smoke is from the rich AFR's.

With out a WB O2 there is not much you can do to know what your AFR is. The only thing you can do is look at the MAF and IDC values to see where they are and guess based on other people that have a WB and what their MAF and IDC values are. This works best if the two cars are the same with the same mods, but it is just a guess. Buy a WB and then you will know what your AFR is.
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Old 03-07-2013, 11:11 PM   #115
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Alright thank you for that explanation it makes sense now. I have a wide band o2 sensor but I need to rewire it and I will do so this weekend.
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Old 03-11-2013, 01:15 PM   #116
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I'm just curious if a cars BPV gasket was leaking what kind of problems will that cause?
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Old 03-11-2013, 01:27 PM   #117
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if you had a leak in your IC it *can* be a vacuum leak under cruise, and a boost leak under boost. Meaning you would run lean in cruise, and rich in boost, with fuel trims to match this.
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Old 03-11-2013, 02:42 PM   #118
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if you had a leak in your IC it *can* be a vacuum leak under cruise, and a boost leak under boost. Meaning you would run lean in cruise, and rich in boost, with fuel trims to match this.
i thought we just went over this?
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Old 03-11-2013, 02:53 PM   #119
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i thought we just went over this?
Sure we did. But I have seen it with my own eyes. BPV was leaking at the gasket caused exactly what I described. Or I should say, it caused positive correction in Areas A , B , and slight negative correction in C, D. Which correlates with a lean condition in low cruise situations(unmetered air getting in AKA a vacuum leak), and in high cruise / boost , a rich condition(metered air being leaked out AKA a boost leak).

Quote:
Originally Posted by veel86 View Post
I'm just curious if a cars BPV gasket was leaking what kind of problems will that cause?
Not trying to start a fight or anything but veel86* asked a question on whether or not a leaky BPV gasket can cause issues, and I described what I have seen the only time I have ever seen a "leaky" bpv gasket.

Last edited by endrswrd; 03-11-2013 at 03:03 PM.
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Old 03-11-2013, 02:54 PM   #120
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Yeah just covered it a week or 2 ago when y'all were helping me out. Just want to add that in my case my IC was leaking and I was getting negative a/f learning numbers under cruise conditions. So weather its rich or lean, an intake tract leak should be the first thing to look at with crazy a/f learning numbers.
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Old 03-11-2013, 04:41 PM   #121
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Originally Posted by endrswrd View Post
Sure we did. But I have seen it with my own eyes. BPV was leaking at the gasket caused exactly what I described. Or I should say, it caused positive correction in Areas A , B , and slight negative correction in C, D. Which correlates with a lean condition in low cruise situations(unmetered air getting in AKA a vacuum leak), and in high cruise / boost , a rich condition(metered air being leaked out AKA a boost leak).
interesting.

mods on the car? obviously enough restriction "upstream" of the throttle plate can cause a vacuum to appear there. the last time my car was stock was 10 years ago.
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Old 03-11-2013, 05:22 PM   #122
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Originally Posted by jebjkey View Post

Are you using 93 oct fuel with the 93 oct map? Knock sensors can go bad, but I would not jump on that just yet. The 93 map has more timing, so it is no surprise that you have more FBKC compared to the 91 map. Try the ACN91 map and see what happens with FBKC.

Your AF Learning value is a little too high. Range C mostly covers cruising around town / on the highway. What are the A, B, and D values? High positive values means the ECU is adding fuel because the amount of air actually reaching the cylinders is more than the amount of air the MAF is reading. This usually points to a vacuum leak and range A and B values should be high also. If they are normal then I would start by cleaning your MAF and see if it there is any change to the AF Learning values.
After cleAning the maf, should u reset the ecu or just drive like that and see if your fuel trims change after the maf cleAning?
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