Car: 2005 wrx wagon 69,xxx miles Catless up, shorty catless down, high flow 3rd cat, cobb cbe, K&N drop in panel filter, Motogp elbow, GMBCS, td04 turbo 1,024 miles on clutch 19,xxx miles on turbo ~1,500 miles on oil (Shell rotella-t) Fresh Shell gas, Only use shell gas or BP Seafoam ran though gas tank after ice races (January '10) Seafoam put in oil for 200 miles after ice races (January '10) Situation: Around December ’09 I started to have what I thought was overboosting on the car. I had Nate (Bullwinkle) take a look at the tune to see if there was something that needed to be adjusted due to the temps outside. When he looked at the tune he said there was nothing out of spec. The car would start to boost up, then it would hesitate, then continue on. After talking about what it could be, Nate suggested that it could my clutch slipping. I remembered that 2 years before this Bikerboy had driven my car and said that he thought my clutch was starting to go. I ordered up a clutch and had Ben and Brian install it for me. When we pulled off the old clutch it was starting to go, but not as bad as they thought it would be (or could be). While performing the install of the new clutch, we ran into an issue. 2 of the 3 studs on my turbo were stripped due to my dumb ass install of my downpipe. Long story short I ended up getting a newer td04 to replace mine. While installing the new td04 we realized that the gaskets used by the original owner of the car were crappy aftermarket gaskets that were leaking where the up-pipe connected to the turbo. We replaced both gaskets on the turbo with Subaru gaskets. Something else to note is we replaced the gasket on the stock bypass valve also. Knowing this leak was there, Ben, Brian, and Nate all recommended a check of the tune after I broke in the clutch. This weekend I had Nate re-look at the tune. After the first pull when he though he had everything cleaned up we went for a 2nd pull. When I got over ~15psi of boost the car hesitated. This was mostly found in the ~3400 to 4000 range if I remember correctly. I’ll have to have Nate give the technical information there. When I say hesitate, the car is building up boost and speed, the kinda “burps” for a second, then starts building up again. I cannot remember if it loses boost or not. Once again I would need Nate to inform about that. My lack of dealing with this issue rendered me worthless, so I looked at Nate. He said I might have a leak somewhere, but recommended I ask the board here for assistance. So, does this sound like a leak? Any ideas of where? My thoughts are I could try re-torqueing the up-pipe in case the bolts started to back off a little, but I trust Ben and Brian 1000% with their work, so unless they tell me to try that I probably won’t mess around with it. Other idea is the stock BPV could be leaking, or maybe another crappy gasket where the uppipe connects to the exhaust manifold. I’m kinda of out of ideas. I haven’t started checking anywhere yet, figured I’d throw this out there to see peoples ideas first. If there’s any key information I’ve left out please let me know. I feel I’ve been pretty good at explaining everything. Thanks so much in advance, Ryan
Did Nate log manifold pressure and wastegate solenoid duty cycle? I'm guessing he would have caught this, but is it possible that it's hitting the boost limit causing fuel cut? Something else would have to be causing it to hit the limit if it was running fine before, ie: bad MAP sensor or leak around the MAP sensor or something that's causing it to over boost and the ecu just protecting stuff. Maybe stuck closed wastegate or stuck open wastegate solenoid?
Good idea, but the car was having the same issue prior to the turbo swap, obviously still something to check, but.. Give me a little credit here . The car's not overboosting or hitting fuel cut. Shouldn't be the WG, as he's tried two turbos now with the same behavior. Could certainly be the BCS malfunctioning somehow. Wiring would throw a CEL, but it could be sticking or something similar. On this note, Ryan, maybe try swapping the BCS with another GMBCS and see if the behavior changes? The car was running fine for a long while (one year?) on the previous tune without problems until last fall/winter. As I told Ryan, my guess is a leak somewhere, but testing the BCS is certainly a good idea. Here's the best log I have of the problem. This is on a stage 2 basemap (hence the low timing) that I've used on dozens of other '05 WRX's. Peak boost is typically around 19 PSI. Only thing I noticed abnormal was that AFR was jumping around a bit, especially at the hesitation point (~4200 RPM), which is about the only really weird thing in the log (and could point to a leak or some fueling problem). Code: afcorr load rpm fbkc flck timing idc iat mrp maf wgfc afr 0 1.26 2656 0 0 21 20.96 72 4.5 55.69 8.63 14.35 0 1.32 2720 0 0 20.5 23.19 72 5.08 59.32 14.9 14.26 0 1.35 2768 0 0 20 23.62 72 5.66 63.99 19.22 13.38 0 1.37 2825 0 0 20 25.12 72 5.95 65.22 25.1 13.33 0 1.4 2925 0 0 19.5 26.21 72 6.24 68.47 29.8 13.26 0 1.44 2989 0 0 19 27.6 72 6.53 72.93 34.12 13.22 0 1.47 3076 0 0 19 29.53 72 6.96 75.81 40.39 12.83 0 1.51 3121 0 0 19 31.4 72 7.55 80.34 44.71 12.88 0 1.57 3227 0 0 18.5 34.42 72 8.13 85.74 50.59 12.76 0 1.65 3296 0 0 17.5 37.98 70 9.14 92.01 55.29 12.69 0 1.74 3346 0 0 17 42.66 70 10.01 98.93 61.18 12.41 0 1.89 3456 0 0 15.5 47.92 70 11.46 110.87 65.88 11.76 0 2.03 3556 0 0 13 54.3 70 12.91 121.18 69.8 11.57 0 2.15 3684 0 0 11.5 58.94 70 14.8 131.81 70.2 11.22 0 2.2 3776 0 0 11.5 61.23 70 15.53 137.83 70.2 11.33 0 2.2 3842 0 0 12 63.1 70 15.82 141.54 70.2 11.35 0 2.19 3985 0 0 12 65.46 70 16.11 146.2 70.59 11.23 0 2.21 4089 0 0 13 67.93 70 15.96 148.06 70.59 11.26 0 2.14 4278 0 0 14 68.45 70 15.82 152.7 70.98 11.10 0 2.2 4271 0 0 14 70.15 70 15.53 155.59 70.98 11.45 0 2.24 4338 0 0 13.5 75.14 70 15.96 165.61 70.98 11.47 0 2.26 4548 0 0 14 78.59 70 15.96 171.77 70.59 11.48 0 2.24 4584 0 0 14 80.19 70 16.11 175.21 69.02 11.20 0 2.22 4738 0 0 14.5 80.4 70 16.11 172.81 66.67 11.10 0 2.21 4789 0 0 14.5 83.72 70 15.67 177.62 63.53 11.00 0 2.15 4870 0 0 15.5 82.21 70 15.09 174.52 61.96 10.88 0 2.1 4977 0 0 15.5 83.92 70 14.22 178.12 59.22 10.79 0 2.07 5067 0 0 16 83.23 70 13.64 180.33 56.47 10.88
Looking at this log again, something weird is going on: Looking at the following rows: Code: 0 2.19 3985 0 0 12 65.46 70 16.11 146.2 70.59 11.23 0 2.21 4089 0 0 13 67.93 70 15.96 148.06 70.59 11.26 0 2.14 4278 0 0 14 68.45 70 15.82 152.7 70.98 11.10 0 2.2 4271 0 0 14 70.15 70 15.53 155.59 70.98 11.45 RPM jumps from 4089 to 4278, and then DOWN to 4271. This explains AFR jumping up at that point. I have seen this before (line mismatching) in logs on Romraider and while tuning, although it was not typically associated with any other mechanical or tune problem.
Well, the log was on an untuned basemap, so slow spool doesn't surprise me in this case. Yeah, I suppose a compression test is a good idea, too.
I figured you would know if that was happening, that was just my best guess, I thought I would just put it out there. It looks like the wfgc is sitting on the max from 3600 to 4300, would the have anything to do with it? Is it bad if it does that, should the tables be adjusted to get ride of that? I ask more cause my car does that, not because I'm doubting your tune.
Well, the WGDC there is maxed, which is why it is static between that range. However, the car should be boosting more in that area with WGDC how they are. Typically if the car wasn't hiccuping, I would've raised WGDC in order to see if I could get more boost out of it, but obviously there is something wrong here as the car should be smooth even with lower WGDC and boost.
Update: Did a compression check, Everything was fine: 1 - 155 2 - 160 3 - 150 4 - 160 Plug were not to spec for the gap, so we changed them out. After that we (Myself, Nuke, and Pheng) took the car for a spin. No more hesitation! Per Nuke, there was some knock though from the logs. The tune isn't tweeked per Nate, so it didn't surprise Nate to hear that. We'll fix that later. Per Ben's recommendation we also ran some seafoam though the intake. The uppipe is leaking where it connects to the manifold, just like Ben thought. I'll need to get that fixed. I want to personally thank the following people, in no particular order: Nuke, Nate, Pheng, Ben, Brian, Sheen, and last but not least.. Fuji.
So just a little update for those who are following. Replaced the leaking gasket only to figure out I have a crack in the weld on my uppipe. Trying to hunt down a stock sti uppipe now, otherwise i'll be looking at aftermarket options.
