Silver Streakin'

I was on my way to meet with the builder of our townhouse that we put a deposit on this past sunday. (We gave up on the single family house as this is a better deal for our 5-year+ plan and we get to make choices along the way ) As long as I didn't boost, it ran fine. But, as soon as I hit any boost, it would misfire and the CEL would come on. I didn't have time to deal with it. I needed to make our appt. So, after catching some dinner with the wifey at a nearby restaurant, I give RKA a call to warn him of my troubles, which could result in my showing up at his place for some more VAGing.

I was hopeful that this might tell me why I'm the I'm not producing the requested boost.

So, since I just put in new plugs on friday before the dyno day, we thought that putting the stock ones back in might solve the issue. So, the wifey goes home in our Wrangler while I pull into a nearby gas station to pull the new plugs and put the old ones back in - which just happen to still be in my tool box that was in the trunk. So, while working on my semi-hot engine while burning my hands on hot coilpacks and plugs, it starts to rain. great. So, I get them back in, start it up, and start to drive it home. stumbles, misfires again. So, it's not the plugs.

I call RKA and he drives out to my place while I'm doing the same.

We find cyl #2 misfiring. I swap coilpack #2 and #3. We find cyl #3 misfiring. It's the coilpack. I just happen to keep one in the car at all times since this is now my 5th coilpack failure.

But, this doesn't solve my falling boost issue.

We log my MAF readings and it's struggling to reach 158 (on GIAC X chip with 94 octane).

We look over the engine bay and can't find any visable things disconnected or obvious leaks.

So, if I'm still seeing normal vacuum readings on my boost gauge, where's the possible leak? MAF going out?

*shrugs shoulders*

yesterday's post of the 115 logs:<ul><li><a href="https://forums.audiworld.com/a4/msgs/2063008.phtml">https://forums.audiworld.com/a4/msgs/2063008.phtml</a</li></ul>

kenny (dremel)

That might help - there's nothing restricting airflow in the airbox (or ducting) right? I think Chris (ModifiedA4) or someone found a bunch of crap in there after winter one year.

You should see max readings of about 170+ around 5-5.5k rpm's.

RKA

I don't think the turbo is drawing in enough air to send the MAF readings any higher. Just not sure why the requested boost is sliding back so quickly.

LaserK04

Does actual follow requested?

I assumed requested boost was mapped by the chip programmer.

kenny (dremel)

do you have a graph? what does the requested peak at?

RKA

Peak on the graph was 2100-2200 mbar. (don't have a graph handy)

Silver Streakin'

X chip (101 octane):

2520 48.1 1100 990
2520 82.7 2020 1050
2560 94 1980 1220
2640 112 2050 1420
2760 133.1 2200 1640
2840 156.4 2310 1910
2920 173.7 2270 2150
3080 177.4 2250 2250
3200 185 2210 2280
3320 184.2 2120 2310
3440 178.2 2190 2250
3600 177.4 2160 2220
3720 173.7 2130 2230
3840 169.9 2120 2210
3960 168.4 2090 2190
4080 166.9 2050 2160
4200 166.2 2030 2130
4320 163.9 2000 2120
4440 160.9 2000 2090
4520 160.2 1980 2050
4640 159.4 1920 2020
4760 157.9 1930 1990
4880 157.1 1950 1970
4960 157.1 1960 1950
5080 154.1 1960 1930
5160 152.6 1960 1910
5240 151.9 1960 1890
5320 148.9 1990 1860
5440 147.4 2000 1830
5520 145.9 1970 1810
5600 144.4 1940 1780
5680 142.9 1930 1770
5760 140.6 1900 1750
5840 139.8 1880 1750
5920 139.1 1840 1740
5960 138.3 1820 1720
6040 135.3 1800 1720
6080 133.8 1800 1720
6160 132.3 1800 1710
6200 130.8 1800 1700
6280 129.3 1800 1690
6360 127.8 1790 1680
6400 127.1 1720 1670
6440 125.6 1690 1660
6520 124.8 1640 1650
6520 50.4 990 1740
6200 14.3 990 1380
4760 115 1760 1200
4800 149.6 1870 1790
4760 48.9 990 1850
4760 14.3 990 1280


XR chip (101 octane):

2320 52.6 990 1080
2400 57.1 990 1090
2440 52.6 990 1100
2440 49.6 990 1090
2480 49.6 990 1080
2520 48.9 990 1080
2520 48.9 990 1080
2560 48.9 990 1080
2560 51.9 990 1080
2600 55.6 990 1090
2640 55.6 990 1100
2680 58.6 990 1110
2720 94 1990 1160
2800 115 2020 1390
2840 138.3 2160 1680
2960 163.2 2160 1970
3080 172.9 2160 2190
3200 182.7 2130 2260
3320 183.5 2110 2310
3440 182 2110 2250
3560 178.9 2070 2260
3680 175.2 2100 2260
3760 172.2 2040 2240
3920 170.7 2070 2220
4040 169.2 2030 2210
4120 166.9 2020 2170
4240 166.2 2010 2150
4360 164.7 1970 2120
4480 162.4 1970 2100
4600 162.4 1930 2070
4680 160.2 1920 2030
4760 157.9 1930 2000
4880 157.9 1960 1990
4960 157.9 1960 1970
5080 154.1 1970 1950
5160 152.6 1970 1920
5280 151.9 1970 1890
5360 149.6 1990 1860
5440 147.4 1980 1820
5520 145.9 1970 1810
5600 144.4 1940 1790
5720 141.4 1930 1770
5800 139.8 1880 1750
5880 139.1 1850 1740
5960 136.8 1820 1740
6040 136.1 1800 1720
6120 133.1 1800 1720
6160 132.3 1800 1710
6280 130.8 1800 1690
6320 127.8 1800 1680
6400 127.1 1790 1660
6440 126.3 1780 1650
6520 129.3 1130 1650
6320 14.3 990 1650
5640 46.6 1560 1200
4720 124.1 1780 1330
4720 94 990 1930
4680 17.3 990 1370
4680 13.5 990 1150
4560 13.5 990 1090
4440 13.5 990 1060
4320 13.5 990 1040
4200 13.5 990 1040
4080 13.5 990 1040
3920 13.5 990 1040
3800 13.5 990 1040

XR chip (101 octane):

2160 75.9 1990 1050
2200 86.5 2020 1150
2280 95.5 2010 1270
2320 104.5 2040 1390
2400 114.3 2070 1510
2480 126.3 2130 1630
2560 140.6 2240 1790
2680 154.9 2220 1960
2800 168.4 2200 2130
2880 172.9 2180 2200
3040 175.9 2170 2230
3120 178.2 2140 2250
3280 182.7 2110 2300
3400 182 2050 2270
3520 177.4 2060 2230
3640 174.4 2040 2220
3760 172.2 2050 2220
3880 169.9 2060 2220
4000 168.4 1970 2200
4120 166.9 1960 2160
4240 164.7 1940 2140
4360 163.9 1930 2120
4440 162.4 2000 2100
4560 162.4 1970 2070
4680 160.2 1960 2040
4760 157.9 1960 2000
4880 157.1 1960 1980
4960 156.4 1960 1950
5080 154.1 1980 1940
5160 151.9 1970 1920
5240 151.1 1950 1890
5360 148.9 1970 1860
5440 147.4 1980 1840
5520 144.4 1970 1810
5600 144.4 1940 1790
5680 142.9 1930 1780
5760 140.6 1900 1770
5800 139.8 1880 1760
5880 139.1 1850 1740
5920 137.6 1840 1750
6000 135.3 1800 1740
6080 134.6 1790 1710
6160 133.1 1790 1710
6200 131.6 1790 1700
6280 130.1 1790 1700
6320 129.3 1790 1680
6360 127.8 1750 1670
6440 126.3 1710 1660
6480 125.6 1700 1660
6600 32.3 990 1850
6240 15 990 1340
4600 120.3 1770 1180
4720 149.6 1950 1800
4680 114.3 990 1930
4680 19.5 990 1420

RKA

On a 3rd gear pull from 2500, requested is higher than actual. As the turbo spools up, actual catches up, and eventually the lines converge and cross, where actual ends up a little higher than requested. Both curves taper gradually after the initial peak. All the while, he's got his foot planted on the throttle.

The car didn't always run the way it does now. It used to pull quite a bit harder with this programming. It's something with the car.

He's going to pressure test on Thursday night. And while he's in there, he's going to poke behind the headlight to look for post maf intake leaks.

I do have a question for you...is there any kind of egt sensor in this car? And what block holds the O2 S1 values, and what values are considered too lean when running WOT in 3rd gear? I'm wondering if a lean condition might be causing a feedback to scale back the requested boost. I'm also thinking it might be time for him to throw in a new O2 sensor. He's got quite a bit of track time on the existing sensor, and probably 55K miles on it. Digit@lex got 80K out of his before his started acting up, but it wasn't exposed to track conditions like jeff's car.

Silver Streakin'

My boost just falls in a straight line from peak at around 3200 RPMs down to 9-10psi.

I'm not holding boost. I watch my boost spike to 19-21 and fall to 9 or 10.

Vacuum readings on my boost gauge at idle are normal.

Ray Khan

and I'm assuming the same $25 02 sensor will work for his primary 02 as it did in mine since he is DBW.