supraGZaerotop Posted July 12, 2017 Author Share Posted July 12, 2017 (edited) Well the drive home from work was really good, seems to be working now altho not perfectly. As I said before, while already up to bypass speeds when I put my foot in it, it launches forward seeing 0.5 and then 0.8. But in a different scenario like just now, i came up on a junction, pulled out and altho i didint mash my foot to the floor i poked it hard enough for it to have boosted, instead just 0.5 up 4k and just seems to rev then pushing the first turbo which of course I then bk off. Got back to the garage and pulled the pressure line off and nothing came out, in ttc I get a massive whoosh. The iacv vsv i have replaced only 4 years ago I'm thinking maybe is a bit duff or I'm thinking can something go wrong with the air valve body the actuator is connected to. Seems as tho I'm losing vac when in sequential but not ttc, and the only difference in that is the vsv are not connected! Is it possible for vsv to leak? Car is much better now anyway so tightening various pipes and replacing the egcv, and cleaning my hks bov and replaced a few more vac lines has done something. Only thing left I know of now is change the lines behind the engine and buy 2 new link pipes on the intake. Edited July 12, 2017 by supraGZaerotop (see edit history) Quote Link to comment Share on other sites More sharing options...
mellonman Posted July 13, 2017 Share Posted July 13, 2017 Boost is alway load dependant so if your not on the loud peddle from the go you will get different readings as you might not alway have the same throttle position, alway check wot throttle to save confusion mate , at this point you should see 0.6 or 7 from first turbo and 0.8 or 9 depending on gear , a bpu car will see 0.7 and 1.1 normally, spraying the egbv arm is never going to hurt and often stops the second turbo coming on . Quote Link to comment Share on other sites More sharing options...
Shane Posted July 14, 2017 Share Posted July 14, 2017 I had months of problems with mine. I would do something and think it was ok, but because I hardly drive it these days when I did occasionally drive for more than a few miles up the road would discover I still had issues. Eventually with CW's help I got to the bottom of it though, mine turned out to be the little link hoses between the hard pipes that run along the bulk head and the engine pipework. A couple of these are an absolute pig to get to, I even read there was some guy on here who dropped his transmission to make access a bit easier.. I cheated and ran two long lengths of re-enforced thick wall quality silicon hose alongside the hard pipes on the bulkhead that replace both the hard pipes and the short silicon joiner hoses. Leaves me with 4 connections instead of 8 so that has to be a bonus. Quote Link to comment Share on other sites More sharing options...
Rob W Posted July 14, 2017 Share Posted July 14, 2017 For the OP Shane is referring to the 2 hard vacuum lines that run to the pressure tank behind the back of the engine block, and yes they are a nightmare to get to if you haven't got anything off in the engine bay! Quote Link to comment Share on other sites More sharing options...
supraGZaerotop Posted July 16, 2017 Author Share Posted July 16, 2017 thanks all, I wont be driving the supra for about 3 weeks now as I'm off work on hols. am I right in thinking having looked at the vac lines! that the pressure tank/turbo side of things are nothing to do with the inlet manifold pressure vac lines? Quote Link to comment Share on other sites More sharing options...
Rob W Posted July 24, 2017 Share Posted July 24, 2017 Just to update. Drove the car for the first time properly over the weekend as I've finally got it all back together. The problem is still there, when applying the loud pedal again then the 2nd turbo boost fine. As I have replaced every vac hose I'm now pretty sure its down to one of the VSV's. When I get some time I might take all of them off and try testing them to see what's what. Quote Link to comment Share on other sites More sharing options...
Scooter Posted July 24, 2017 Share Posted July 24, 2017 Rob appreciate the update, shame yours didn't get fixed but interesting in the big scheme of things re a resolution. I need to stop being lazy and get cracking on mine as I have a fully working bpu car, so I should swap one by one the vsv's over until my stock car works as intended. I also have a spare set of vsv's but not 100% they all work as they should, so should fit these to the bpu car instead of the stock cars ones and check them this way (or on the bench). I have some evenings free next week so will get on it then hopefully. Quote Link to comment Share on other sites More sharing options...
Rob W Posted July 24, 2017 Share Posted July 24, 2017 (edited) To be fair, after all the work I've done recently to the car taking off the vsv's to test is a nice easy job compared:) I've just got to read on up how to test them properly and might try and fins time this week. Edit: Just came across this link, think it shows everything I need to know. http://wilbo666.pbworks.com/w/page/65646659/2JZ-GTE%20Sequential%20Turbo%20System Edited July 24, 2017 by Rob W (see edit history) Quote Link to comment Share on other sites More sharing options...
Burna Posted July 24, 2017 Share Posted July 24, 2017 To be fair, after all the work I've done recently to the car taking off the vsv's to test is a nice easy job compared:) I've just got to read on up how to test them properly and might try and fins time this week. Edit: Just came across this link, think it shows everything I need to know. http://wilbo666.pbworks.com/w/page/65646659/2JZ-GTE%20Sequential%20Turbo%20System Great info, thanks Rob Quote Link to comment Share on other sites More sharing options...
Rob W Posted July 24, 2017 Share Posted July 24, 2017 Well I decided to take off the IACV and the EBV VSV's tonight as they are the easy ones and only took a couple of minutes. Tested them following that link earlier, both are fine and seem in working order so next will be to test the wastegate and EGCV VSV on the 1st turbo. The only thing I was thinking whilst doing it, I know we are checking to see the solenoid working but what if it's the signal to VSV's? I have no idea how you would go about testing the signal inputs. Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted July 24, 2017 Share Posted July 24, 2017 (edited) My BPU also gave alot of issues, no boost, erratic boost, boost only after pressing the throttle twice. To get it running properly, I recommend the following. 1. Change all VSV's 2. Change all Vac hoses 3. Change the black link pipes on the inlet to the two turbos. 4. Change pressure tank 5. Find new or low mileage IACV & EGCV and install. I changed the IACV, got 0,1bar more boost, had to back the EBC settings down. Have a new EGCV valve waiting to go in. I tried repairing the car as I came across the problems, was time consuming and frustrating. With the age of the car, if you fix one issue, another one will pop up. As an example, I was getting erratic boost, IACV VSV was the culprit. Changed that, problem was solved. Was heading out to race my mates 1M, the new IACV VSV failed at that moment, had no boost. After changing the above 5 items, I had to back the EBC settings back by 20%. Basically to reach 1.2bar my EBC was working 20% harder because of all the inefficencies in the system. What this translated to in power was 18wkw & 31nm power gain. Fuel consumption improved dramatically, dropped from over 24l/100km to 15l/100kms. Car is now making 270wkw on 102octane fuel.. So in summary.. change everything on the sequential system and enjoy the car as it would have been new. Edited July 24, 2017 by Samurai 20V (see edit history) Quote Link to comment Share on other sites More sharing options...
Scooter Posted July 30, 2017 Share Posted July 30, 2017 Ok finally got some time to look at mine.......and without tempting fate it seems to be fixed. Ok I'll list what I did, as anyone tackling this knows it's almost a real ball ache to do only one thing and test, then anther etc, so I'll list all the bits i did (not many) before testing and it all seemingly fixed. Ok starting point was to gather up my sundry hoses! Quote Link to comment Share on other sites More sharing options...
Scooter Posted July 30, 2017 Share Posted July 30, 2017 (edited) Ok so I started by looking at the rear most turbo hoses, mainly because I knew I had to change the hoses over there from being in TTC. Firstly excuse the Heath Robinson, hose type, lengths and use of electrical tape! but this is testing and in my book the niceties can go on hold. So firstly the pipes in the foreground pictured in blue and the one immediately to it's right were both easy to rotate at one or both joints, so were removed and replaced with the ones you see. The non blue one I used a stock item that was removed from my other (lower mileage) TT when I did it's 1st turbo mod (note I did this after trying my other hoses - but the plastic vsv (lower) joint has a large diameter than the upper metal pipe joint which meant is was hard to get a tight fit on both and I didn't want to force it on the plastic for fear of snapping it, also it's quite an acute turn for a straight hose) Ok some of the hose joints i wrapped tape to pad out the diameter to ensure the hose clip clamped better. Then I moved to the two pipes in the back ground (note just for info) when I removed one I got a hiss re air from the pressure tank - this was after not using the car for well over a week). Now these are the ones that are swapped for TTC, I checked my other car to pop them back to sequential fitting but again noticed where they had been on different pipes the ends had flared slightly making them a loose fit on the plastic vsvs. So I got some pipe reserves but again wasn't too happy with the snugness of the fit on the two vertical vsv connections (the two nearer the front of the car - one is at the end of the very heath robinson pipe that comes over the top of the heater matrix pipe) so I wrapped some tape around the plastic vsv stub connections before popping the hoses on. Note these hoses are the ones with no clips/clamps just held on by friction. Edited July 30, 2017 by Scooter (see edit history) Quote Link to comment Share on other sites More sharing options...
Scooter Posted July 30, 2017 Share Posted July 30, 2017 I then removed the airbox to give me better access to the front hoses that I need to switch from TTC back to sequential. There didn't seem to be any hose issues here (the ones you switch i'd replaced when first going TTC) but I did grab the arm (thin rusty one in front of the engine mount) in the attached pic and gave it a few pushes and pulls to check it's action and ensure it moved smoothly (I think this arm moves a flap in the exhaust at transition???) Quote Link to comment Share on other sites More sharing options...
Scooter Posted July 30, 2017 Share Posted July 30, 2017 (edited) Ok hard to get a pic of this, but after moving the arm above I decided I would try and do the same with the actuator/plunger at the rear just in from the camcover. I used some scissors and if you go in the direction of the photo down the side of the cam cover, by the throttle cable support nut, you can flick a lever up and the rod extends down out of the cylinder bit you can see. (I really need to be able to put some 'paint' arrows in on this pic - sorry) Doing these things seems to have fixed mine, I went out and selected 2nd and it transitioned fine, then on the motorway limited to 3rd it was fine, 4th and kickdown again fine, slow speed and double kickdown to 2nd again fine, now this was only for a few miles, i'll report back on whether it stays ok! Edited July 30, 2017 by Scooter (see edit history) Quote Link to comment Share on other sites More sharing options...
Burna Posted July 30, 2017 Share Posted July 30, 2017 (edited) Good write up Scooter Put mine in TTC mode on Friday, and just took a run over Telford to test it. Second turbo always comes on boost now, and tbh I love TTC mode so far! Great sound and even more fun! I guess because I'm in TTC mode and my second turbo is always coming online now, that points to a problem with my vsv's only? Am I correct? Edited July 31, 2017 by Burna (see edit history) Quote Link to comment Share on other sites More sharing options...
Scooter Posted July 30, 2017 Share Posted July 30, 2017 It points to vsv's or the pipework to/from them. I thought I probably had a vsv issue but i only touched pipework today, I just had a general fumble around and worked on any joins that felt suspect? Mine like yours worked fine in TTC and it has a novelty effect but at stock boost/with cats it really stifles the low down grunt, yours may cope better/feel less of a loss. Quote Link to comment Share on other sites More sharing options...
Tsia Posted July 30, 2017 Share Posted July 30, 2017 A couple of years ago on mine i had the same issue and it turned out to be one of the vacuum pipes had come off, it was a small U shape pipe and you could stare at it for 10 minutes and swear blind it was connected when in fact 1 side had just come off. My symptom was second turbo wasn't kicking in, if i backed off the throttle a little then it worked fine. I have attached an image showing roughly where the pipe was.[ATTACH=CONFIG]220251[/ATTACH] I had this exact problem a few years ago and it was the same problem. Pipe had come off Quote Link to comment Share on other sites More sharing options...
Burna Posted July 31, 2017 Share Posted July 31, 2017 It points to vsv's or the pipework to/from them. I thought I probably had a vsv issue but i only touched pipework today, I just had a general fumble around and worked on any joins that felt suspect? Mine like yours worked fine in TTC and it has a novelty effect but at stock boost/with cats it really stifles the low down grunt, yours may cope better/feel less of a loss. Mine must be a vsv, as it would work from cold, but as soon as the car got hot the second turbo would come on intermittently after kicking it down a few times. if it was a pipework problem surely it wouldn't be coming on at all? I really like the feel of it in TTC mode, it has less low down grunt now and would probably be better on a manual car, but I really like the feel of the boost curve, lot less of a crash over to the second turbo like it is in sequential on a BPU car. I can imagine with the cats in it could be quite a sluggish feel low down, but I have no cats or restrictor ring, just 3" all the way through to the RSR exhaust, sounds like a beast in TTC lol Quote Link to comment Share on other sites More sharing options...
Scooter Posted July 31, 2017 Share Posted July 31, 2017 (edited) The noise definitely goes up (again not noticeable in a stock car!) Mine was the same (well would do it from cold and hot) and it's fixed (drove it to work today to keep testing it) without changing a vsv. I 'think' some pipework can be leaking and it will only affect/upset the transition phase, however despite reading Ian C's threads a few times, I couldn't talk anyone through the exact air flow that goes on in each piece of pipe at each part of the rev range, so perhaps not, but I don't think every small pipe you see turbo side has to be completely intact to get any boost. Personally I would check thoroughly the pipework/joints first especially the hoses that are just push fit with no clamps/clips. Edited July 31, 2017 by Scooter (see edit history) Quote Link to comment Share on other sites More sharing options...
Scooter Posted August 6, 2017 Share Posted August 6, 2017 Ok just some more sundry info. I have a whole turbo side of spares from James now single Jewel green Supra. So I fished out the exhaust valve, one of the things pictures above airbox side down by the inner wing. Now as far as I know this is the flap that in TTC gets held open and in sequential at low revs is completely shut. So it's crucial in the sequential operation and is last in the chain of events. The air pressure, acts on the arm, which via a pivot point acts to open the flap in the exhaust to allow exhaust to flow into the 2nd turbo? When I got it out to check it over, on the exhaust flap pivot there is a screw/bolt set up that sets the backstop of the flap. Now why is this here, specifically why is it adjustable? I've used the car more recently and it's been a lot better but still occasionally I get the over 4000rpm and it's just not going like it should and I believe the flap is still closed for some reason. I'm going to clean and lube the arm to try and make it slicker, also i'm wondering if the flap is sticking/slightly gummed up internally so I may adjust the screw/backstop piece so the flap is closer to opening or even very very slightly open (obviously this will be guess work as I won't be able to actually see inside the one on the car. Quote Link to comment Share on other sites More sharing options...
supraGZaerotop Posted August 15, 2017 Author Share Posted August 15, 2017 took mine out the other day after 3 weeks. still not right ahahahahahah. but then im still to change the firewall vac lines and intake link pipes. Quote Link to comment Share on other sites More sharing options...
supraGZaerotop Posted August 15, 2017 Author Share Posted August 15, 2017 when you ttc and plumb the pressure lines straight to the actuators, does this means the actuators are fine? Quote Link to comment Share on other sites More sharing options...
supraGZaerotop Posted September 3, 2017 Author Share Posted September 3, 2017 bump Quote Link to comment Share on other sites More sharing options...
Scooter Posted September 3, 2017 Share Posted September 3, 2017 I think it means the pressure tank is fine as is the second turbo afaik, not sure what else it proves as such. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.