I Donated thefultonhow Posted May 7, 2013 I Donated Share Posted May 7, 2013 The last couple of days, I've had a strange problem with my Spec.B. When the engine is cold, I can hit 20psi (which is what the tune is set for). Once it warms up, I only hit 9-10psi. For some reason, when this happens, the max WGDC is in the 30s. Vacuum lines all seem to be fine. I am running a BNR Evo 16G and a Grimmspeed 3-port EBCS, plus UP, DP, etc. Car drives fine otherwise. Thoughts? Link to comment Share on other sites More sharing options...
05pearl Posted May 7, 2013 Share Posted May 7, 2013 Could be several items. On the surface, it would seem some item is expanding enough (when the temp rises) to cause a leak on the pressure side of the turbo. I was thinking something could also be expanding to mess with the WG, but you said it's only at 30%. Link to comment Share on other sites More sharing options...
rob-2 Posted May 7, 2013 Share Posted May 7, 2013 What's your tmic look like? Any oil leaking? Have you gone over the intake connections? Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted May 7, 2013 Author I Donated Share Posted May 7, 2013 What's your tmic look like? Any oil leaking? Have you gone over the intake connections? TMIC is bulletproofed. All vacuum hoses on the intake are intact, and the manifold gaskets have been done. Could be several items. On the surface, it would seem some item is expanding enough (when the temp rises) to cause a leak on the pressure side of the turbo. I was thinking something could also be expanding to mess with the WG, but you said it's only at 30%. Yeah, that's the thing that gets me. I would think, if there was a leak, that WGDC would be much higher. A new twist -- today, on the drive to work, the engine was cold but it was still only boosting to 10psi. Link to comment Share on other sites More sharing options...
05pearl Posted May 7, 2013 Share Posted May 7, 2013 A new twist -- today, on the drive to work, the engine was cold but it was still only boosting to 10psi. Actually, that may make it easier to find the problem. Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted May 7, 2013 Author I Donated Share Posted May 7, 2013 Actually, that may make it easier to find the problem. Yes, but any ideas? Link to comment Share on other sites More sharing options...
05pearl Posted May 7, 2013 Share Posted May 7, 2013 Smoke test for leak... Link to comment Share on other sites More sharing options...
rob-2 Posted May 7, 2013 Share Posted May 7, 2013 TMIC is bulletproofed. All vacuum hoses on the intake are intact, and the manifold gaskets have been done. Yeah, that's the thing that gets me. I would think, if there was a leak, that WGDC would be much higher. A new twist -- today, on the drive to work, the engine was cold but it was still only boosting to 10psi. I don't normally enter boost until the car is warmed up. I'm surprised no one has mentioned this. Since the turbo is able to produce the boost you have a leak. These I have little to no experience tracking down. Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted May 7, 2013 Author I Donated Share Posted May 7, 2013 I don't normally enter boost until the car is warmed up. I'm surprised no one has mentioned this. I try not to,, but was doing so in this case for diagnostic purposes. Since the turbo is able to produce the boost you have a leak. These I have little to no experience tracking down. I really think it's a problem in the boost control system, not a leak. Fuel trims are roughly okay, and the really low WGDC indicates to me that the wastegate isn't closing enough to build boost. Furthermore, if it were just a leak, then it would max out at 10psi all the time, not 20psi, then 10psi, then 20psi, then 10psi. Has anyone heard of a Grimmspeed EBCS going bad? Link to comment Share on other sites More sharing options...
05pearl Posted May 7, 2013 Share Posted May 7, 2013 It could be your ebcs - try putting in a cheap manual boost controller and see what happens. If it boosts, then it's your Grimmspeed. If it does not boost, then check for leak. Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted May 7, 2013 Author I Donated Share Posted May 7, 2013 I think I will try with my stock BCS. Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted May 7, 2013 Moderators Share Posted May 7, 2013 I think I will try with my stock BCS. Do you have a tune for that? "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
05pearl Posted May 7, 2013 Share Posted May 7, 2013 Stock BCS may work fine just to check to see if it boosts. No need to worry about tune if you back off throttle immediately. There may be a simple way to block for switch/modify/block hoses going to the boost controller to allow for uncontrolled boost. If so, you could simply do a very quick throttle push when driving to see if boost climbs well past 10psi. If it boosts, that would also indicate problem with Grimmspeed. If not, then check for leak. Unfortunately, I don't recall what you may/may not be able to do with those hoses to allow for this. You should be safe as long as you back off the throttle once you see boost go well over 10psi. Link to comment Share on other sites More sharing options...
DeltaNu1142 Posted May 7, 2013 Share Posted May 7, 2013 I have a used Grimmspeed EBCS sitting here in a USPS small flat-rate box if you want to give it a try. Tits mcgee Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted May 7, 2013 Moderators Share Posted May 7, 2013 I have one on my car also if you want to try it. Would need to come to Springfield. "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted May 7, 2013 Author I Donated Share Posted May 7, 2013 I have one on my car also if you want to try it. Would need to come to Springfield. I might take you up on that. Maybe not today, though... Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted May 7, 2013 Author I Donated Share Posted May 7, 2013 Okay, so I put the stock BCS and lines back on, and I can hit 11-12psi. No other changes. What gives? Link to comment Share on other sites More sharing options...
05pearl Posted May 8, 2013 Share Posted May 8, 2013 It's possible the tune was for the Grimmspeed, so that's why you may see slightly different boost on the stock BCS. But, since you are tuned for about 20psi, that would indicate a leak somewhere on the pressure side of the turbo. Smoke test should find the leak. If you have a fmic, you may want to quickly tighten up the coupler clamps to see if any are loose. Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted May 8, 2013 Author I Donated Share Posted May 8, 2013 Um, as a general rule, boost will go down if you switch from a Grimmspeed 3-port to the stock BCS. And a leak wouldn't make any sense, considering boost was at 20psi, then 10psi, then 20psi, and then 10psi again. Also, I don't have an FMIC. Link to comment Share on other sites More sharing options...
fahr_side Posted May 8, 2013 Share Posted May 8, 2013 Leak makes little sense but failing BCS might. Fitting a stock BCS to a car tuned for a 3-port will not result in overboost, it's the other way round you have to be careful with. I'd suggest bypassing the BCS completely to see if you get solid, steady boost at spring pressure. If you could borrow a manual boost controller for a test that would confirm you can get steady boost at higher pressures. Might be easier to pick another 3-port, doesn't have to be a GS item, they all work the same way. Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs. Link to comment Share on other sites More sharing options...
4CEF3D Posted May 8, 2013 Share Posted May 8, 2013 Could the hot side of the turbo have cracked like they do sometimes and your loosing exhaust pressure threw the crack in the wastegate? Just a thought. Link to comment Share on other sites More sharing options...
Mega Users seabass07 Posted May 8, 2013 Mega Users Share Posted May 8, 2013 The low WGDC should rule out a leak pretty quickly. Also a LV would be a good idea for ruling it out. A leak should result in max WGDC since the ecu will be trying to compensate for being below target. Just another thought...Couldn't a sensor failing cause lowered WGDC? Isn't there a coolant temp compensation for WGDC? Don't have romraider near me at the moment to check. Link to comment Share on other sites More sharing options...
BAC5.2 Posted May 8, 2013 Share Posted May 8, 2013 The low WGDC should rule out a leak pretty quickly. Also a LV would be a good idea for ruling it out. A leak should result in max WGDC since the ecu will be trying to compensate for being below target. Just another thought...Couldn't a sensor failing cause lowered WGDC? Isn't there a coolant temp compensation for WGDC? Don't have romraider near me at the moment to check. I believe you are correct on the coolant temp sensor. But that would also manifest itself in hard-starting, right? Obvious first diagnostic step is to log. [URL="http://legacygt.com/forums/showthread.php/proper-flip-key-interesti-159894.html"]Flip Key Development Thread[/URL] "Genius may have its limitations, but stupidity is not thus handicapped." - E. Hubbard Link to comment Share on other sites More sharing options...
fahr_side Posted May 8, 2013 Share Posted May 8, 2013 I believe you are correct on the coolant temp sensor. But that would also manifest itself in hard-starting, right? Not to mention a CEL. Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs. Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted May 8, 2013 Author I Donated Share Posted May 8, 2013 Also a LV would be a good idea for ruling it out. Can't. Because Accessport. Obvious first diagnostic step is to log. I have a crappy log that I'm attaching.datalog24.csv Link to comment Share on other sites More sharing options...
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