ryansupra Posted June 15, 2013 Share Posted June 15, 2013 (edited) Hi guys, I need help! I just purchased a 96 jspec.. Mods are Mine's ecu, Kakimoto cat-back, HKS Evc 4 and K&N air filter. I drove it today and it doesnt feel right. The minute i accelerate, turbo spools right away in any gear. It pulls till 4k or so then dies down. Boost gauge shows 0.7 in 2nd gear, 1.1 over 3rd gear. It also depends how i set the EVC, lower boosts if i up the offset. The issue is past 4k rpm. Lets say i have the Evc set for 1.1bar.. Till 4k it holds but past that it drops to 0.5 and stays there. I searched and search and could not get a straight answer. I admit, the turbo system is too complex and I'm finding hard to understand how it works. I got the basics but can somebody point me to which valve/pipe i should inspect? Also, around 3.5k, there is a jerk in boost.. Any ideas will be well appreciated. Ryan Edited June 26, 2013 by ryansupra (see edit history) Quote Link to comment Share on other sites More sharing options...
Guigsy Posted June 15, 2013 Share Posted June 15, 2013 Mine used to do this occasionally after being sat for a while. It was a sticky valve in the boost pipework/exhaust. After a fre runs giving it 100% throttle it freed its self up and has been fine since. Other than that it might be a blown 2nd turbo. But I'd imagine you would be getting more significant pointers towards that. I'm no mechanic though. So take that with a pinch of salt till someone who knows what they are doing posts Quote Link to comment Share on other sites More sharing options...
Wez Posted June 15, 2013 Share Posted June 15, 2013 First thing first I would bypass the EVC and put it back to stock following the guides on here, if you still have a problem then it will be a VSV or turbo Quote Link to comment Share on other sites More sharing options...
supra steveo Posted June 15, 2013 Share Posted June 15, 2013 i had that and the 2nd turbo only spooled up for a few seconds turned out to be the EGCV VSV and what had happened was one of the bits that the pip goes onto had snapped so just bypassed the VSV and plumbed the car up to run true twin so now at 3K RPM both turbos step in Quote Link to comment Share on other sites More sharing options...
mellonman Posted June 15, 2013 Share Posted June 15, 2013 Read this Quote Link to comment Share on other sites More sharing options...
mplavery Posted June 15, 2013 Share Posted June 15, 2013 Read this mate Few things you can check ... My guess is a split vacuum hose If you find the fault, take a pic of the problem and add it to the thread to help other people http://mkivsupra.net/vbb/showthread.php?257946-No-Boost-on-2nd-Turbo-SOLVED-***NOT-SOLVED******&p=3246702#post3246702 Quote Link to comment Share on other sites More sharing options...
ryansupra Posted June 15, 2013 Author Share Posted June 15, 2013 First thing first I would bypass the EVC and put it back to stock following the guides on here, if you still have a problem then it will be a VSV or turbo The dealer i bought if from told me that once he bypassed the Evc and put it back to stock, it stayed solid 0.7 bar all the way. I bave yet to try that. Can an Evc go bad if that is the case? Quote Link to comment Share on other sites More sharing options...
Guest Budz86 Posted June 15, 2013 Share Posted June 15, 2013 Would more likely mean that it hasn't been set up properly. Sounds like you have a problem with the 2nd turbo though - probably the IACV not opening so any boost from the second turbo can't make it into the engine. As Scott says, bypass the EVC to check it's not that then check all the vac hoses - there are 2 down the back of the engine that are a pain to get at but due to their location, they suffer from heat and tend to go brittle first. If that doesn't work it's time to start changing VSV 's! Quote Link to comment Share on other sites More sharing options...
ryansupra Posted June 16, 2013 Author Share Posted June 16, 2013 Is there a way to test the vsv's manually? For example, if i rev up the engine while the hood is open, any of the vsv get active at any point for me to see? Quote Link to comment Share on other sites More sharing options...
Guest Budz86 Posted June 16, 2013 Share Posted June 16, 2013 Apparently you can see them working on the dyno but don't think they would work at standstill as you need pressure from the system to operate it - turbos need to be under load iirc Quote Link to comment Share on other sites More sharing options...
mellonman Posted June 16, 2013 Share Posted June 16, 2013 If you set it to ttc then they should stay open, and you can test them to a degree with a multi meter as seen in the toyota repair manauls on the home page Quote Link to comment Share on other sites More sharing options...
ryansupra Posted June 23, 2013 Author Share Posted June 23, 2013 So i put her in TTC and still no boost past 4k. I bypassed the IACV VSV and the EGCV VSV . Boost was delayed a bit as it should, went up to 1 bar for a second then drops right away to 0.5 bar and stays there. Car feels like it has no power. Also, i noticed that if i turn off the EVC4, car still boosts up to 1 bar on 3rd gear before 4k rpm. Isnt it suppose to go to stock boost when it is turned off? I also unplugged the IACV pipe right after i parked and no air came out. Does that mean i VSV might be ok but i have a leak somewhere from the air tank?I cant really see the tank under the inlet. I reached in but cant feel it either. What else should i check? Quote Link to comment Share on other sites More sharing options...
thetrashcanman Posted June 23, 2013 Share Posted June 23, 2013 So i put her in TTC and still no boost past 4k. I bypassed the IACV VSV and the EGCV VSV . Boost was delayed a bit as it should, went up to 1 bar for a second then drops right away to 0.5 bar and stays there. Car feels like it has no power. Also, i noticed that if i turn off the EVC4, car still boosts up to 1 bar on 3rd gear before 4k rpm. Isnt it suppose to go to stock boost when it is turned off? I also unplugged the IACV pipe right after i parked and no air came out. Does that mean i VSV might be ok but i have a leak somewhere from the air tank?I cant really see the tank under the inlet. I reached in but cant feel it either. What else should i check? Check all the Vac lines, if air is coming out of one of those it just won't open the VSV to allow the second turbo to come online Quote Link to comment Share on other sites More sharing options...
ryansupra Posted June 24, 2013 Author Share Posted June 24, 2013 Check all the Vac lines, if air is coming out of one of those it just won't open the VSV to allow the second turbo to come online I did, i don't see any air escaping and looked at all the lines. I also removed the EVC completely and i have the same symptoms. It boosts to 0.7 up to 4k then drops to 0.5. I removed the IACV VSV pipe right after i shut the engine off and no air came out. Some air should come out, right? If the problem is an air leak, which pipes should i diagnose? Also, both EGCV and IACV move freely when pushed down with a screw driver. Sorry for asking too many questions.. Trying to learn this system slowly, hopefully get it fixed. Thanks Quote Link to comment Share on other sites More sharing options...
Tromen Posted June 24, 2013 Share Posted June 24, 2013 I had similar problem my 2nd turbo wouldnt kick in. Found out that the thick rubber pipe that connects between the two turbos, the inner side of it had collapsed which made the 2nd turbo hard to spool. Replace it and things were back to normal Quote Link to comment Share on other sites More sharing options...
ryansupra Posted June 24, 2013 Author Share Posted June 24, 2013 I had similar problem my 2nd turbo wouldnt kick in. Found out that the thick rubber pipe that connects between the two turbos, the inner side of it had collapsed which made the 2nd turbo hard to spool. Replace it and things were back to normal Thanks... i will check it out tomorrow. Mind telling me which one? There are two of them, one on top and the other further down. Quote Link to comment Share on other sites More sharing options...
ryansupra Posted June 24, 2013 Author Share Posted June 24, 2013 Thanks... i will check it out tomorrow. Mind telling me which one? There are two of them, one on top and the other further down. I removed all pipes linking both turbos and they are fine. I will keep looking. Quote Link to comment Share on other sites More sharing options...
Sukhy Posted June 24, 2013 Share Posted June 24, 2013 Check the piping that goes towards the firewall on the right hand side (inlet side when standing infront) to the pressure tank. Then follow it anti-clockwise towards the turbos to see if there is a split in any of those lines. Quote Link to comment Share on other sites More sharing options...
ryansupra Posted June 24, 2013 Author Share Posted June 24, 2013 Check the piping that goes towards the firewall on the right hand side (inlet side when standing infront) to the pressure tank. Then follow it anti-clockwise towards the turbos to see if there is a split in any of those lines. I cannot seem to find the pressure tank. Do i need to remove the intake manifold to access it? I ran a few tests today and got some positive results.... I used 2 small grippers to hold the IACV and EGCV actuator arms open. Went for a spin and both turbos are working. Car is fast and i still have the EVC disconnected. I am thinking of leaving it this way by permanently opening both actuators. The exhaust was a little louder too and the rush of boost at 4k is amazing! I know it is not really solving the issue but i have to say that TTC is the way to go.. Thanks for all the help guys Quote Link to comment Share on other sites More sharing options...
Tromen Posted June 25, 2013 Share Posted June 25, 2013 Did u convert it to true twin mode Quote Link to comment Share on other sites More sharing options...
ryansupra Posted June 25, 2013 Author Share Posted June 25, 2013 Did u convert it to true twin mode Yes i did. Not really sure where the problem is but this solution made the car run great. Here are some pics of what i did.. I made two rods that hold the IACV and EGCV actuators open at all time. Car is a little bit louder which i like and the boost rush at 4k is amazing. The lower end turbo lag isn't that bad, definitely good enough. Let me know what you think Quote Link to comment Share on other sites More sharing options...
thetrashcanman Posted June 25, 2013 Share Posted June 25, 2013 Yes i did. Not really sure where the problem is but this solution made the car run great. Here are some pics of what i did.. I made two rods that hold the IACV and EGCV actuators open at all time. Car is a little bit louder which i like and the boost rush at 4k is amazing. The lower end turbo lag isn't that bad, definitely good enough. [ATTACH=CONFIG]171630[/ATTACH] [ATTACH=CONFIG]171631[/ATTACH] Let me know what you think Surely that would mean that there's probably something wrong with one of the actuators then, if you can't find any split in the boost hoses, but in TTC mode the car pulls okay then I would guess it would be one of the actuators that your forcing open is at fault. What boost does the car make with that mod and in TTC mode? Quote Link to comment Share on other sites More sharing options...
ryansupra Posted June 26, 2013 Author Share Posted June 26, 2013 Surely that would mean that there's probably something wrong with one of the actuators then, if you can't find any split in the boost hoses, but in TTC mode the car pulls okay then I would guess it would be one of the actuators that your forcing open is at fault. What boost does the car make with that mod and in TTC mode? I do not think that there is anything wrong with the actuators cause there is no air in the system. When i park and pull IACV hose, no air comes out which means the system is not pressurized. I have a feeling the pressure tank is bad or the hoses coming from it. No EVC attached, she boosted up to 0.7 psi max. I have her at 1.1 bar max with Hks Evc4. Whoever never tried TTC, should go for it.. + it feels more fuel efficient Quote Link to comment Share on other sites More sharing options...
thetrashcanman Posted June 26, 2013 Share Posted June 26, 2013 I do not think that there is anything wrong with the actuators cause there is no air in the system. When i park and pull IACV hose, no air comes out which means the system is not pressurized. I have a feeling the pressure tank is bad or the hoses coming from it. No EVC attached, she boosted up to 0.7 psi max. I have her at 1.1 bar max with Hks Evc4. Whoever never tried TTC, should go for it.. + it feels more fuel efficient Ah yes I think you might be right, could indeed be the pressure tank. and yup TTC mode is actually quite good, and yes it is more fuel efficent as your not on boost until around 3-3,500rpm as the first turbo isn't online in the normal way which it would be around 2000rpm, means the car loses some low down torque, but you gain in the mid range. Quote Link to comment Share on other sites More sharing options...
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