Bradley1500 Posted November 21, 2017 Share Posted November 21, 2017 Last winter my Supra would randomly not hit full boost. This would last for anything from one minute to thirty minutes, and then would be fine again for ten minutes or a couple of days. There was no clue as to why the car was doing this and no pattern to what was causing it. Come the summer and the car ran fine and hit full boost consistently. I cannot remember it ever not hitting full boost during the warmer weather. I thought the problem had sorted itself, but with the colder weather we have had recently the car has started playing up again. I don’t know whether this is a coincidence or not. The car is a TT6 with BPU modifications, including: HKS SSQV, HKS induction, HKS FCD, Walbro 255LPH, Blitz Nur Spec exhaust, Garage Whifbitz first decat and HKS secondary decat. The car typically boosts to 1 bar, but when playing up will be limited to 0.6-0.7 bar. The exhaust note also changes and instead of the usual BOV noise, it tends to flutter more. What could be causing this? I have a boost controller and FMIC which I will be fitting soon, so I will see if either of these affect anything. In the meantime I would appreciate any advice on simple things to checkout. Quote Link to comment Share on other sites More sharing options...
Scooter Posted November 21, 2017 Share Posted November 21, 2017 Could it be the same delayed/no second turbo per below? http://www.mkivsupra.net/vbb/showthread.php?343594-sequential-issue-and-going-ttc-ideas-please Quote Link to comment Share on other sites More sharing options...
Bradley1500 Posted November 21, 2017 Author Share Posted November 21, 2017 Could it be the same delayed/no second turbo per below? http://www.mkivsupra.net/vbb/showthread.php?343594-sequential-issue-and-going-ttc-ideas-please I'm not sure I have the same problem as I can still feel the second turbo kick in, just not as strong as it normally would. The best way to describe it is as a boost leak allowing a slight pressure drop, except it will fix itself. Sometimes I will be WOT when it decides to hit full boost again. There is no rhyme or rhythm to it. Thanks for the link though. I will have a read through and see if I can garner any ideas from it. Quote Link to comment Share on other sites More sharing options...
Scooter Posted November 21, 2017 Share Posted November 21, 2017 Well the normal go to test is to put it in TTC mode so the sequential system isn't running and see if you get back to full boost (careful the first time as the boost can often go higher than normal - but if you are at 1.0bar it should be fine and only go to 1.1-1.2) Quote Link to comment Share on other sites More sharing options...
Bradley1500 Posted November 21, 2017 Author Share Posted November 21, 2017 Well the normal go to test is to put it in TTC mode so the sequential system isn't running and see if you get back to full boost (careful the first time as the boost can often go higher than normal - but if you are at 1.0bar it should be fine and only go to 1.1-1.2) Thanks. If it consistently hits full boost when in TTC mode, what would this indicate as the original problem? Quote Link to comment Share on other sites More sharing options...
Mk4Gaz Posted November 21, 2017 Share Posted November 21, 2017 The most common reason for this, is one of the vsv failing - normally the iacv vsv. If you download the tsrm app, and grab a multimeter, it's dead easy to test them. Quote Link to comment Share on other sites More sharing options...
Scooter Posted November 22, 2017 Share Posted November 22, 2017 Yes it's not that helpful in that 'part of the sequential system isn't working' but as Gaz said it's then down to a vsv or split hose/hose joint etc. Quote Link to comment Share on other sites More sharing options...
Bradley1500 Posted November 22, 2017 Author Share Posted November 22, 2017 Thanks both. I had ruled out split hoses as the problem is intermittent. Am I right in thinking that if a hose was split it would be a constant problem? If that assumption is correct, I will look into replacing all VSVs. I have a spare turbo setup in the garage, hopefully I have the old VSVs with it too. Quote Link to comment Share on other sites More sharing options...
Bradley1500 Posted November 22, 2017 Author Share Posted November 22, 2017 If you download the tsrm app, and grab a multimeter, it's dead easy to test them. I have just tried downloading the TSRM app but it doesn't work on IOS 11. I will try downloading it on an old phone or my iPad later on as I don't think I have updated either of those yet. Quote Link to comment Share on other sites More sharing options...
Mk4Gaz Posted November 22, 2017 Share Posted November 22, 2017 Ah, yes, the developer of the app hasn't updated it for ios 11. If I get time today, I'll look up the pages you need, and screen shot them on here Quote Link to comment Share on other sites More sharing options...
Bradley1500 Posted November 23, 2017 Author Share Posted November 23, 2017 Ah, yes, the developer of the app hasn't updated it for ios 11. If I get time today, I'll look up the pages you need, and screen shot them on here /QUOTE] Thank you, very kind. I managed to download the app on my iPad last night, but haven't yet had a chance to look through it to find the bits I need. I'm hoping I will have time at the weekend to take a look at the car, so will likely have an update then. Quote Link to comment Share on other sites More sharing options...
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