Guest Jason1 Posted May 26, 2014 Share Posted May 26, 2014 Hi again Need a little advice on this My car is a tt auto, and sometimes when I drive the car I can floor it and by Christ it goes mental lol really throws me back in the seat and I struggle to keep hold of it. However I can park up then go out again and its like half the power is missing just isn't as quick and although the boost gauge shows .8 bar it just doesn't feel like it did 10 mins ago I have looked at all the vac lines and every thing looks right and plugged on correctly, today I put the standard bov back on (same) The one thing I have noticed though is according to the vac diagram on the bonnet it shows the fpr going into a vsv but mine doesn't have this just goes straight to the map sensor and little gas filter thingy,, Anyone have any clues? as driving me mad and I need to get it sorted before I put a ebc on it. Thanks Quote Link to comment Share on other sites More sharing options...
Gpro Posted May 26, 2014 Share Posted May 26, 2014 On the image below where the arrow is pointing "cap this to keep dirt out" check the actual connector and the wires are pushed in hard. Seen many of these with loose connections cause the exact issue your saying http://mkiv.supras.org.nz/images/articles/andy03.jpg Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted May 26, 2014 Share Posted May 26, 2014 The FPR (intake manifold side) goes straight back to the manifold, no VSVs included. Quote Link to comment Share on other sites More sharing options...
Guest Jason1 Posted May 26, 2014 Share Posted May 26, 2014 On the image below where the arrow is pointing "cap this to keep dirt out" check the actual connector and the wires are pushed in hard. Seen many of these with loose connections cause the exact issue your saying http://mkiv.supras.org.nz/images/articles/andy03.jpg Thanks for that May car is still standard at the moment so the vsv is still being used and the pipes are on and that bit is still plugged in. Unless of course I can bypass it that way, would it cause a engine light on if I do this? Swampy Thanks for the info don't know why it shows a vsv in that line I thought it was funny. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted May 26, 2014 Share Posted May 26, 2014 All the VSVs are to do with sequential turbo control, on the exhaust side of the engine. The FPR and MAP sensor are on the intake side and go straight back into the intake manifold for the best pressure reference. In instances like this, a picture paints a thousand words Quote Link to comment Share on other sites More sharing options...
Guest Jason1 Posted May 26, 2014 Share Posted May 26, 2014 This is the reference I used It does show the fpr then a vsv before it the goes to the map sensor Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted May 26, 2014 Share Posted May 26, 2014 Is that a US spec picture? Id guess so with the EGR system fitted. There is a VSV under the intake manifold but thats to do with the charcoal canister. Quote Link to comment Share on other sites More sharing options...
Guest Jason1 Posted May 27, 2014 Share Posted May 27, 2014 That would explain it Anyway today it doesn't seem to bad, last night I unplugged every sensor and plug I could find Gave them a squirt of WD and then plugged them back in, Seems to be a lot better today, also the exhaust note deepens at around3.7k so I am presuming that the exhaust valve is opening. We will see how I get on as the 2nd decat pipe should be here this week and so this will give me a full decat, 2 1/2" front pipe the rest 3" I am hoping this should be ok without a restrictor? Thanks Quote Link to comment Share on other sites More sharing options...
listy Posted May 27, 2014 Share Posted May 27, 2014 NOOOOOOOOOOOOOOOOO!!!!!!!!!!! If you are removing both cats, it WILL NOT be ok without a restrictor ring. Your turbos will boost way too high and pop. Quote Link to comment Share on other sites More sharing options...
Scooter Posted May 27, 2014 Share Posted May 27, 2014 NOOOOOOOOOOOOOOOOO!!!!!!!!!!! If you are removing both cats, it WILL NOT be ok without a restrictor ring. Your turbos will boost way too high and pop. Or as he says it's stock, he'll hit fuel cut... Quote Link to comment Share on other sites More sharing options...
listy Posted May 27, 2014 Share Posted May 27, 2014 (edited) Fuel cut won't stop it boosting higher in higher gears though. I only ever used to hit fuel cut in first gear. Edited May 27, 2014 by listy (see edit history) Quote Link to comment Share on other sites More sharing options...
supra_ufo Posted May 27, 2014 Share Posted May 27, 2014 have you tried TTC? Failing that it could be the VSV I had a half working one and after BPU it was showing 0.8 BAR in sequential and 1.2 in TTC Quote Link to comment Share on other sites More sharing options...
mellonman Posted May 27, 2014 Share Posted May 27, 2014 Fuel cut won't stop it boosting higher in higher gears though. I only ever used to hit fuel cut in first gear. Listy fuel cut is activated if you go above 1 bar, regardless of what gear or speed Quote Link to comment Share on other sites More sharing options...
listy Posted May 27, 2014 Share Posted May 27, 2014 Listy fuel cut is activated if you go above 1 bar, regardless of what gear or speed In that case, I stand corrected. I never experienced it in higher gears, probably due to the RR in place. I only ever had fuel cut in first gear. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted May 27, 2014 Share Posted May 27, 2014 You should, if anything, experience it more in higher gears due to the extra load on the engine. Quote Link to comment Share on other sites More sharing options...
Guest Jason1 Posted May 28, 2014 Share Posted May 28, 2014 Hmm I thought by having a 2 1/2" front pipe to a 3" would be a restrictor? How do you restrict the system, were would a get a restrictor ring? Quote Link to comment Share on other sites More sharing options...
Mk4Gaz Posted May 28, 2014 Share Posted May 28, 2014 A restrictor ring is generally a 2" hole in a flat piece of metal, cut to the same shape as the gasket between the first and second decat. Mine is about 4mm thick from memory. Whifbitz or Chris Wilson could probably help you out, unless you're any good at cutting thick metal sheet? Your boost issue sounds like a failed iacv vsv, it was the exact same on mine. I switched to ttc mode, to rule out the pressure tank, and it boosted fine. A new vsv, back to sequential, and all is well again. The bgb has instructions for how to test it, that's how I realised mine was duff Quote Link to comment Share on other sites More sharing options...
Guest Jason1 Posted May 28, 2014 Share Posted May 28, 2014 Thanks for that I am going to try to TTC it before I fit the 2nd decat I could probably make a restrictor with a 2" hole We have some 4mm metal at work I will fit it between front and 2nd pipes Just got to sort out the correct way to TTC it now as there is so many versions I don't know which one to use. Quote Link to comment Share on other sites More sharing options...
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