caseys Posted May 2, 2011 Share Posted May 2, 2011 Evening all, Been looking at my boost controller as it appears I can't get boost pressure above 0.7 bar currently. Normally : Controller off - wastegate spring pressure = 0.5 bar - absolutely fine Controller low setting (set to 1.0 bar) = 0.7 bar - holds at 0.7bar, doesn't fluctuate Controller hi setting (set to 1.2 bar) = 0.7 bar - holds at 0.7 bar, doesn't fluctuate Gain and such has not been changed, it's spooling absolutely fine, building boost as it normally would just hits a ceiling at 0.7 bar, not getting deafened by the screamer etc - let off on low/high setting on WOT definitely doesn't give the huge whoosh of pressure that it used to. Removed all hoses and pressure tested all fine. Both Greddy Profec B2 reporting 0.7 bar as is the HKS boost gauge as well. Am I right in thinking the solenoid / controller is knackered and isn't bleeding properly and so just letting the wastegate open at 0.5 (spring setting when controller bypassed) or 0.7 when controller in use (i.e. solenoid not holding it closed). Apologies did do a search on this, maybe I'm not using the right terminology. Quote Link to comment Share on other sites More sharing options...
caseys Posted June 30, 2011 Author Share Posted June 30, 2011 Well, having bought a boost solenoid and fitted it tonight it's made no improvement, in fact if anything I wonder if it's got worse : Controller off - 0.4 bar (I am actually wondering if I have a 0.7 bar spring) Low setting - 0.7 bar Hi Setting - 0.7 bar Can definitely hear the screamer pipe going when we hit 0.4 bar when the controller is off - wastegate is definitely opening. Could there be a component in the wastegate that's broken which means it's not holding desired boost? Spring? Diaphragm? But then my understanding is that the solenoid basically bleeds off boost sent to the wastegate to open until reaching a desired pressure? Help anyone?? Quote Link to comment Share on other sites More sharing options...
SimonB Posted June 30, 2011 Share Posted June 30, 2011 Are you sure it's not a split intercooler hose or one that's blown off? Quote Link to comment Share on other sites More sharing options...
caseys Posted June 30, 2011 Author Share Posted June 30, 2011 Are you sure it's not a split intercooler hose or one that's blown off? I admit haven't checked for a split. If it had blown off surely id have zero boost? Quote Link to comment Share on other sites More sharing options...
Lude Posted June 30, 2011 Share Posted June 30, 2011 no if it splits you have some boost & lose some boost. ive just sorted my EBC, mine was overboosting, mine was just split hose/not fitted on 100% Quote Link to comment Share on other sites More sharing options...
Guest Importcars.at Posted July 1, 2011 Share Posted July 1, 2011 Try to check the filter between the boost controler and there you get the pressure! (You know the little white or black one) Maybe that could help! We also had 3 times the same problem! Roman Quote Link to comment Share on other sites More sharing options...
TubbyTwo Posted July 1, 2011 Share Posted July 1, 2011 I had the same problems with my MR2 Turbo, replaced all the hose clamps on the larger hoses with new strong ones and replaced all the boost lines and it was fine. Quote Link to comment Share on other sites More sharing options...
Scott Posted July 1, 2011 Share Posted July 1, 2011 (edited) This doesn't sound like your boost controller Si, sounds like something else is up. The boost controller solenoid basically sits between the turbo and the wastegate. The solenoid stays firmly shut, not bleeding, until the desired boost level is seen from the turbo. When the boost level is reached (or slightly passed depending on gain AFAIK) the solenoid then opens, the pressure then opens the wastegate and exhaust gas is released. The solenoid then fluctuates to keep the desired boost level. If you have the controller set at 1.0bar, and the solenoid is OK, then it would really point to the system losing pressure somewhere.... or, worst case scenario, the turbo not being able to produce the pressure because of damage. I would recommend getting yourself a manual boost controller. That way when things like this do happen you can quickly check if the boost controller is at fault. Do the obvious checks first though (intercooler pipes, split hoses, compressor vanes of the turbo, shaft play, free turning, etc). Edited July 1, 2011 by Scott (see edit history) Quote Link to comment Share on other sites More sharing options...
caseys Posted July 1, 2011 Author Share Posted July 1, 2011 Thanks for the replies Guys, Turbo sounds just as it used to when running 1.2 Bar, but haven't taken it apart yet. Friend's going to get it on his 4-poster on a spare day and we'll take the bumper off and do a thorough check for anywhere which could be leaking. Also got to find a manual for my boost controller, the paper one I have is well, oily! Quote Link to comment Share on other sites More sharing options...
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