Scott Posted April 24, 2010 Share Posted April 24, 2010 are the vsv specific to the car. Can a bust one not be replaced by on that works. ie changing the two related to turbo 2 What I mean is... the VSV's aren't specific to turbo 1 or turbo 2. They are specific to the sequential system. Different VSV's do different jobs. You can't just take the one nearest tubby 1 and put it on the place nearest tubby 2, they both do completely different jobs. What you need is an EGBV VSV Quote Link to comment Share on other sites More sharing options...
gavin.starr Posted April 24, 2010 Author Share Posted April 24, 2010 Ah right get you. whats the EGBV stand for i cant remember. I could do a random change of the spare VSV's and see if it makes a difference. Its worth a try seeing as i have 2 propperly working examples Quote Link to comment Share on other sites More sharing options...
Scott Posted April 24, 2010 Share Posted April 24, 2010 Ah right get you. whats the EGBV stand for i cant remember. I could do a random change of the spare VSV's and see if it makes a difference. Its worth a try seeing as i have 2 propperly working examples Exhaust Gas Bypass Valve. They aren't all the same spec. You should know by looking at it which one is which. Check out the MKIV Technical Section and have a look for "the Sequential System". Very nice write up by Ian C covering most of the bases. Quote Link to comment Share on other sites More sharing options...
gavin.starr Posted April 24, 2010 Author Share Posted April 24, 2010 Ah ok ill take a look at what ive got tommorow. Cheers for your help fella, most apreciated. gav Quote Link to comment Share on other sites More sharing options...
Homer Posted April 24, 2010 Share Posted April 24, 2010 As Scott has mentioned, the very likely cause of this is a sticky or faulty EGBV, VSV's do go faulty, but more often than not it's the EGBV actuator. It is very common and becoming more so as these engines get older. Pain is the ass to fix though. Edit - best to get the VSV's changed first to rule them out, that's an easy job Quote Link to comment Share on other sites More sharing options...
gavin.starr Posted April 24, 2010 Author Share Posted April 24, 2010 What does the EGBV actuator look like, ie where is it in the engine bay. Is it the one on the top near the rear if your stood looking at the car from the front. Quote Link to comment Share on other sites More sharing options...
Homer Posted April 24, 2010 Share Posted April 24, 2010 What does the EGBV actuator look like, ie where is it in the engine bay. Is it the one on the top near the rear if your stood looking at the car from the front. EDIT - I meant the EGCV, not the EGBV, sorry! It's difficult to see as it's under the turbo's. http://www.mkivsupra.net/vbb/attachment.php?attachmentid=13944&d=1112559002 Look for EGCV actuator and housing labels, they are essentially a single part. Quote Link to comment Share on other sites More sharing options...
Scott Posted April 24, 2010 Share Posted April 24, 2010 As mentioned "The Sequential System" by Ian C Quote Link to comment Share on other sites More sharing options...
gavin.starr Posted April 24, 2010 Author Share Posted April 24, 2010 ive literally just replaced that actuator last weekend (what a pig of a job) so it must be the vsv controlling it thats at fault then? Quote Link to comment Share on other sites More sharing options...
Scott Posted April 24, 2010 Share Posted April 24, 2010 This thread needs an "auto reply" Quote Link to comment Share on other sites More sharing options...
gavin.starr Posted April 24, 2010 Author Share Posted April 24, 2010 Quote Link to comment Share on other sites More sharing options...
Homer Posted April 24, 2010 Share Posted April 24, 2010 Did I miss something Have you already replaced the EGCV and housing section with a known working one? If that's the case there's only a couple of things it could be, obviously the simple one (EGCV vsv) is next on the list. Can't see how the BV would cause an intermittant complete loss of boost to the 2nd turbo. If it were faulty it'd cause steady boost increase after 4k rpm rather than a complete loss of 2nd turbo boost. Quote Link to comment Share on other sites More sharing options...
Steve Posted April 24, 2010 Share Posted April 24, 2010 http://www.mkivsupra.net/vbb/showthread.php?t=35926 Just in case no one has mentioned this thread. Quote Link to comment Share on other sites More sharing options...
gavin.starr Posted April 24, 2010 Author Share Posted April 24, 2010 (edited) Yea i changed the EGCV actuator and exhaust flange, with the one that i took off my car when turbo number 2 blew. the one that i removed was rattling from the actuator arm where it attaches to the valve in the exhaust, so i thought it may have been that, thats why i changed it back to my orrigional because i thought it could be something to do with that which was causing the problem. Sometimes but not very offen turbo 2 wont come on from 1st through to 3rd gear, it will usually only come on if i accelarate hard from a standing start and then it will com on, but say im driving normally and pull out to overtake in 3rd gear i get nothing. Edited April 24, 2010 by gavin.starr (see edit history) Quote Link to comment Share on other sites More sharing options...
gavin.starr Posted April 24, 2010 Author Share Posted April 24, 2010 Can't see how the BV would cause an intermittant complete loss of boost to the 2nd turbo. Whats the BV stand for, im not a fan of abreviations as i get very easly confused when im learning new things Quote Link to comment Share on other sites More sharing options...
Scott Posted April 24, 2010 Share Posted April 24, 2010 Blowoff Valve. You have changed the actuator, now change the thing that controls the actuator. Make sure you check all the vac lines at the same time. Feel like a broken record here It's so funny too, as you have done the hard part Quote Link to comment Share on other sites More sharing options...
gavin.starr Posted April 24, 2010 Author Share Posted April 24, 2010 (edited) Im feeling really tired now when you say chaqnge the thing controlling the actuator you mean the EGVC VSV. Honestly my head is mashed, im hard training for a half marathon so ive been on a 14mile run not so long ago. think im ready for bed. Edited April 24, 2010 by gavin.starr (see edit history) Quote Link to comment Share on other sites More sharing options...
Scott Posted April 24, 2010 Share Posted April 24, 2010 Im feeling really tired now when you say chaqnge the thing controlling the actuator you mean the EGVC VSV. Honestly my head is mashed, im hard training for a half marathon so ive been on a 14mile run not so long ago. think im ready for bed. Yes, and the lines coming to/from it. Quote Link to comment Share on other sites More sharing options...
gavin.starr Posted April 24, 2010 Author Share Posted April 24, 2010 ok cheers fella, its taken a while but we have got there in the end i hope, i think this is one of the spare VSV's ive got so i my be in with a bit of luck. ill keep you informed tommorow. Cheers for your help its most appreciated Gav Quote Link to comment Share on other sites More sharing options...
Homer Posted April 24, 2010 Share Posted April 24, 2010 Sometimes but not very offen turbo 2 wont come on from 1st through to 3rd gear, it will usually only come on if i accelarate hard from a standing start and then it will com on, but say im driving normally and pull out to overtake in 3rd gear i get nothing. This is the typical sign of a control valve issue, but it seems you guys have been discussing this already and ruled that out, so will leave you to it Still can't see how the bypass valve can cause this if the boost has more or less zero build after the 1st turbo is engaged... Hope you get a good resolution to this PS: If you get stuck for VSV's, I have a box or two of them here. Quote Link to comment Share on other sites More sharing options...
Scott Posted April 24, 2010 Share Posted April 24, 2010 Fancy selling me a whole set Darryl? If you can't spare a set can you part with an IACV and a EGCV? Quote Link to comment Share on other sites More sharing options...
gavin.starr Posted April 24, 2010 Author Share Posted April 24, 2010 Without going into detail which controll valve is usually at fault, just so that i can take a look at things propperly with a fresh head in the morning Quote Link to comment Share on other sites More sharing options...
gavin.starr Posted April 24, 2010 Author Share Posted April 24, 2010 This is the typical sign of a control valve issue, but it seems you guys have been discussing this already and ruled that out, so will leave you to it Still can't see how the bypass valve can cause this if the boost has more or less zero build after the 1st turbo is engaged... Hope you get a good resolution to this PS: If you get stuck for VSV's, I have a box or two of them here. Fancy selling me a whole set Darryl? If you can't spare a set can you part with an IACV and a EGCV? Looks like your search for VSV's may have been answered Quote Link to comment Share on other sites More sharing options...
Scott Posted April 24, 2010 Share Posted April 24, 2010 IACV, the one on the very top at the rear. Quote Link to comment Share on other sites More sharing options...
gavin.starr Posted April 24, 2010 Author Share Posted April 24, 2010 Ok cheers ill double check it in the morning. Just out of intrest is there any way of re-furbing the vsv or is it a case of once there dead there dead Quote Link to comment Share on other sites More sharing options...
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