Dazzi Posted May 10, 2008 Share Posted May 10, 2008 Right, this is the situation: Flooring my n/a in 3rd gear the revs build up and when they get to around 4000 revs power decreases by about 200revs like it takes a breather and the suddenly power comes back. This pause lasts about 1.5 seconds. Is it something to do with the ECU? If I replace the ECU will it smooth out? Its not really a problem, just strange to explain to mates Quote Link to comment Share on other sites More sharing options...
dibbleyuk Posted May 10, 2008 Share Posted May 10, 2008 Sounds like a sticky butterfly mate thats what i was told when i had a guy look at my Dyno sheet. Quote Link to comment Share on other sites More sharing options...
Dazzi Posted May 10, 2008 Author Share Posted May 10, 2008 Hmmm, say if I floor it it happens but if I floor it say 2 mins later it doesn't do it. Besides last night I was fixing my high idle and sprayed the butterfly with wd40 so who knows... Quote Link to comment Share on other sites More sharing options...
bromy Posted May 10, 2008 Share Posted May 10, 2008 This is around the point in the rev range it switches from short to long runners (or the other way around) nothing to worry about, it is noticable on the dyno sheet. The flap is located here Dip in dyno Quote Link to comment Share on other sites More sharing options...
kieren1234 Posted May 10, 2008 Share Posted May 10, 2008 It wouldnt drop 200 rpm for 1.5 seconds though would it. Dont think mine ever did as n/a? Quote Link to comment Share on other sites More sharing options...
Dazzi Posted May 10, 2008 Author Share Posted May 10, 2008 Here is a good example but the break is shorter and the revs drop by a 1.5k: http://uk.youtube.com/watch?v=7eE74vUhqFY 1st time its floored (1:08) you can clearly see the dip 2nd time (2:40) its smooth Thanks for the help so far Quote Link to comment Share on other sites More sharing options...
Dazzi Posted May 10, 2008 Author Share Posted May 10, 2008 This is around the point in the rev range it switches from short to long runners (or the other way around) nothing to worry about, it is noticable on the dyno sheet. The flap is located here http://i7.photobucket.com/albums/y262/kimberley1979/3arrow.jpg Dip in dyno http://i7.photobucket.com/albums/y262/kimberley1979/rr2.jpg hmm I wonder if this is the flap that is sticking? As said before it does it the 1st time its floored Quote Link to comment Share on other sites More sharing options...
miko_supra Posted May 10, 2008 Share Posted May 10, 2008 i think i still have this part of the manifold with this "flap" in it lying around if you need it Quote Link to comment Share on other sites More sharing options...
Dazzi Posted May 10, 2008 Author Share Posted May 10, 2008 i think i still have this part of the manifold with this "flap" in it lying around if you need it Cheers mate, Might strip it and clean around and see how it goes Quote Link to comment Share on other sites More sharing options...
Rob Posted May 10, 2008 Share Posted May 10, 2008 Move the yellow arrow to the right, to the middle of the big plenum. That's where the butterfly is. Oddly, when I run with the 2nd cat in, I really notice a surge in power at 5000rpm as that valve operates, yet it's hardly there when fully catless. Quote Link to comment Share on other sites More sharing options...
Dazzi Posted July 26, 2008 Author Share Posted July 26, 2008 This is still happening but not sure what else to do. Theres a couple of things it might be. I've read the fuel pump stays at 9v until you floor it which then increases to 12v. Im just wondering if the fuel pump needs replacing? Its not running lean... also the 3rd gear on my car has the most amount of play and power so you never know, the clutch might not be planting the power down when dumping.. Quote Link to comment Share on other sites More sharing options...
Jay_vr6 Posted July 27, 2008 Share Posted July 27, 2008 I'm the same as Rob, with my catless system the car is completely smooth through the rev range, with the first cat back in i get the same surge, but def not 1 sec powerloss or so, i have a sport clutch so get great instant grip when rolling through the gears at high revs, it could be that though, would you not get any sort of sound if it was the clutch ? Quote Link to comment Share on other sites More sharing options...
Rob Posted July 27, 2008 Share Posted July 27, 2008 If the clutch were playing up it would slip, so revs would rise, not fall, at the moment in question. Quote Link to comment Share on other sites More sharing options...
Dan8 Posted July 27, 2008 Share Posted July 27, 2008 Mine does it to if you floor it it pauses when gets to this revs mine manual though but if you keep driving it this way for e g country lanes it only does it the 1 s t flooring i gave it but if i stop flooring it for a while then do it again it does the same thing mine has a fuel press with gauge running at 38 and a high pressure high flow pump and still does it Quote Link to comment Share on other sites More sharing options...
Dan8 Posted July 27, 2008 Share Posted July 27, 2008 What mods are done to the n a with that graph Quote Link to comment Share on other sites More sharing options...
Dazzi Posted July 28, 2008 Author Share Posted July 28, 2008 If the clutch were playing up it would slip, so revs would rise, not fall, at the moment in question. Thats a good point actually. I got into my head if it slipped the revs would go down but yea, I get it. What mods are done to the n a with that graph NA-T conversion that graph is from Quote Link to comment Share on other sites More sharing options...
Dazzi Posted August 2, 2008 Author Share Posted August 2, 2008 (edited) I finally got round to double decatting the car yesterday and this problem which I think is a flat spot is still there. I think i've narrowed it down to: 1. One or more ignition coil(s) 2: Air flow meter 3: Fuel pressure regulator 4: Butteryfly valve Control 5: Removal of the stock airbox Come to think of it the supe had TT BPU plugs in when I bought it and changed them to na plugs... will pop the old ones in and see Edited August 3, 2008 by Dazzi (see edit history) Quote Link to comment Share on other sites More sharing options...
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