Can't boost past 10psi...wastegate and vacuum lines ok!!
Apr 7, 2009, 09:30 PM
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Can't boost past 10psi...wastegate and vacuum lines ok!!
About two weeks ago I lost half my boost pressure. I had a hallman MBC installed and it worked fine for 4 months until about 2 weeks ago. I searched all the forums on here and everyone says a stuck open wastegate, boost control solenoid, or kinked vacuum lines. Ive checked everything and its all fine, and even took off the MBC and put it back to stock and am still only boosting 9-10pounds. I am completely lost. Im not showing any codes either. I have exhausted all the existing posts on this subject with no solution....does anyone have any other ideas??????? PLEASE HELP!!!! i need my adrenaline rush back!!
Thanks in advance!!!
Thanks in advance!!!
Apr 7, 2009, 09:38 PM
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inside your wastegate, there is a little rubber diaphragm, check to see if that's not blown, because if it is, you will not be able to gain boost because, i believe, the wastegate flapper stays open or something of that nature.
Apr 7, 2009, 10:51 PM
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any unusual new noise since the incident, did you check all your intercooler piping connections, n blow some compressed air quickly to your waste gate to check if it still shuts once you let off the air, and check for turbine play? ive gone through two stock turbos and no codes showed up when i blew them up
Apr 7, 2009, 10:56 PM
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You are going to hate hearing this but, make yourself a boost-leak test. This happened to one of my friends and we checked everything, focusing around the EBC and in the end, it was a vacuum hose that had a small slit in it.
Apr 8, 2009, 03:14 PM
#5
This is a question.
If the boost gauge gives good vacuum reading (like mine @ 20mmHg) when engine running at idle, would that elimate a vacuum problem.
Actually I'm experiencing the same thing and ppl say its my fuel filter thats dirty or my fuel pump sending me failure warnings.
Very confused.
If the boost gauge gives good vacuum reading (like mine @ 20mmHg) when engine running at idle, would that elimate a vacuum problem.
Actually I'm experiencing the same thing and ppl say its my fuel filter thats dirty or my fuel pump sending me failure warnings.
Very confused.
Apr 9, 2009, 12:32 AM
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Check all upper and lower intercooler sleeves, see if any slid off causing to lose power or if any damage to it. Does the wastegate sounds like it flutter? Check that as well...good luck
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Apr 9, 2009, 03:35 PM
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there are no strange noises. the turbine spins freely. it sounds normal when boosting and my stock BOV still releases with no fluttering from that or the wastegate. its slow to spool up and when it gets up to about 9 lbs it maintains and doesnt taper off which wouldnt suggest a leak from a coupler. my vacuum pressure also maintains and doesnt fluctuate at idle. the fuel filter could be it maybe, cuz a few weeks prior i was showin a fuel code for the pump itself. If anyone knows a shop in riverside or orange county that is reasonable and reputable for evos ill take it in cuz I dont have the time to put into it right now. Im just tryin to avoid the dealership so I dont get raped in cost. I appreciate any and all feedback!! 
Apr 9, 2009, 07:49 PM
#12
i have the exact same problem. started yesterday after boostin hard 3rd n 4th. i have the hallman mbc with adjuster in car also on a 35r. i did have a leak at my tb shaft seals before but i dont think it would leak enough to drop from 24 psi to 10..but n e ways i ordered new ones and should have them by friday. ill install them and redo all my couplings on my piping and get new lines for the mbc. ill let you kno what happens. i hope its just a vacc leak cus i really dont feel like buying a new WG. lemme kno if u figure it out first. we might have the same problem
Apr 12, 2009, 10:12 PM
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Well i did the boost leak test today and the intake track and pipes only hold 9-10psi, same as my boost gauge said when im driving. But i still could not find the leak. it held 10psi for about 20 seconds before tapering down to zero, but there is no hissing!!! no sounds what so ever! any other ideas of where an inaudible leak could be coming from????
Thanks
Thanks
Apr 18, 2009, 07:51 PM
#14
ay i just finished the tb shaft seals and replaced alot of vac lines ...buutttt still didnt help. did a leak test and had no leaks so i dont kno what else to check. any one got n e ideas? could it b the hallman bc? do they ever fail? jdeinert did you ever fix your problem?
Apr 18, 2009, 10:55 PM
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im still stuck. i did the boost leak test and i only hold 10psi. i removed the bumper and redid all the intercooler piping, tightened down all the hose clamps and checked all vacuum lines....there is no audible leak....is it possible to have an internal leak???? im so lost!
