08SpecB_DE Posted April 12, 2016 Share Posted April 12, 2016 Hey guys, I want to start off by saying my car is bone stock. I was looking at some live data earlier and my manifold relative pressure reading went to around 16psi in Intelligent mode and shot up to 25psi in sport mode. At idle it's reading around -19.5. Any thoughts? I was thinking about checking the waste gate operation first but would like some input. Link to comment Share on other sites More sharing options...
acumenhokie Posted April 12, 2016 Share Posted April 12, 2016 Do you have any datalogs from a good pull? Link to comment Share on other sites More sharing options...
08SpecB_DE Posted April 12, 2016 Author Share Posted April 12, 2016 I do not. I bought a new snap on scanner so I figured I'd play with it a little bit. What kind of data are you referring to? Link to comment Share on other sites More sharing options...
solidxsnake Posted April 14, 2016 Share Posted April 14, 2016 How are you reading these numbers? The boost and vacuum numbers look too large in absolute value (stock boost in I mode should be less than 13psi, and vacuum shouldn't be much less than -11psi while cruising). I wonder if the units are messed up? Link to comment Share on other sites More sharing options...
Tuning Alliance Posted April 14, 2016 Share Posted April 14, 2016 Hey guys, I want to start off by saying my car is bone stock. I was looking at some live data earlier and my manifold relative pressure reading went to around 16psi in Intelligent mode and shot up to 25psi in sport mode. At idle it's reading around -19.5. Any thoughts? I was thinking about checking the waste gate operation first but would like some input. Are you on a cobb ots map? I suggest getting an ETUNE at the very least. These maps are known to pull timing, knock, and blow motors. If you want, send us a PM and we can get you started on a proper tune, and we'll troubleshoot along the way if we come into this problem. From what it sounds like its wastegate related. -Brian Contact us for all your tuning and performance parts needs! Etuning the legacy community since 2008! Follow us on FACEBOOK | INSTAGRAM [sIGPIC][/sIGPIC] Link to comment Share on other sites More sharing options...
08SpecB_DE Posted April 15, 2016 Author Share Posted April 15, 2016 Solidsnake- I'm reading manifold relative pressure with my snap on solus edge scanner. Should I be reading absolute pressure instead of the mrp? TuningAlliance- I am not on any tune as far as I know. I have no idea what the po did to this car. I just recently found out my cluster is reading 17k more miles than what my scan tool is picking up directly from the computer. I don't typically hit full boost while daily driving and it didn't seem have any fuel cut out or other issues indicating something is wrong. I can do a waste gate test with my scanner this weekend and make sure it's functioning properly. Link to comment Share on other sites More sharing options...
solidxsnake Posted April 15, 2016 Share Posted April 15, 2016 If you're stock, you would have hit fuel cut at those boost pressures...chances are you've got a tune on there. I'm assuming your OBD scanner is reading the numbers correctly (I'm not sure if different scanners would misread parameters). Manifold relative pressure is the correct parameter. Take it for a drive, log MRP, target boost, wastegate duty cycles, and throttle position. Other useful parameters to log are feedback- and fine-learn knock correction, AF correct and MAF. Link to comment Share on other sites More sharing options...
LatentWagen Posted April 15, 2016 Share Posted April 15, 2016 All good advice above ^ OP, before you go logging, check your vac/boost signal lines, too. Especially the one that goes from the turbo to the WG actuator. A pin hole or crack in that signal line would create the overboosting symptoms you're describing. LW's spec. B / YT / IG Link to comment Share on other sites More sharing options...
08SpecB_DE Posted April 15, 2016 Author Share Posted April 15, 2016 Will do guys, thanks for your insight! I'll see what I come up with and let you all know. Link to comment Share on other sites More sharing options...
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