Problem with supercharger setup. (bypass valve not opening)
Problem with supercharger setup. (bypass valve not opening)
I'm using the bypass valve from a cooper S that's controlled by vacuum.
The problem is that when the vacuum drops and the car is receiving boost it starts to accelerate uncontrolled until you release the throttle. Almost like you had full throttle but you barely touched it.
Also if you accelerate and then releasing the throttle again without closing it completely it will just continue to accelerate but just a little less aggressive. If I then don't release the gas completely or give more throttle the car will go in to some fail(safe) mode. Then it wont be possible to give any throttle at all, if so the engine will die. Sometimes it clears itself after a few seconds and other times it needs a restart to go away.
The problem seems to be that it wont create vacuum. When the problem occurs there is still over pressure in the manifold even though almost no throttle is applied.
Another thing I noticed is that the vacuum seems to disappear quite early.
I've taken out the spring in the bypass valve and loosen it up alot. Originally I think it's supposed to open at -6psi but now it's really loose and does take much less vacuum to open. Although this didn't help. Actually I don't think it's the bypass valve that's causing the problem. Because as long there is over pressure in the manifold, that pressure will keep the bypass valve shut.
I checked the throttle positioning with an odb interface in my phone. Although closed throttle is around 16% open and full throttle is about 79% open according to it, the tps sensor seems to be the same and follow the gas pedal the same with the charger on as without. (Probably)Ruling out that the boost pressure forces the throttle to open more.
Btw, the vacuum hoses I firstly used where to weak so I'm using fuel hoses now instead.
Some pictures of how he bypass valve is connected.
https://dl.dropboxusercontent.com/u/1153....10.55.jpg
![[Image: Namnl%C3%B6s.png]](https://dl.dropboxusercontent.com/u/11530547/Outlaw%20jap%20club%20forum/Namnl%C3%B6s.png)
Just installed a supercharger and are experiencing some problems with my setup that I can't get my head around. Hoping that maybe you guys might be able to help me out
I'm using the bypass valve from a cooper S that's controlled by vacuum.
The problem is that when the vacuum drops and the car is receiving boost it starts to accelerate uncontrolled until you release the throttle. Almost like you had full throttle but you barely touched it.
Also if you accelerate and then releasing the throttle again without closing it completely it will just continue to accelerate but just a little less aggressive. If I then don't release the gas completely or give more throttle the car will go in to some fail(safe) mode. Then it wont be possible to give any throttle at all, if so the engine will die. Sometimes it clears itself after a few seconds and other times it needs a restart to go away.
The problem seems to be that it wont create vacuum. When the problem occurs there is still over pressure in the manifold even though almost no throttle is applied.
Another thing I noticed is that the vacuum seems to disappear quite early.
I've taken out the spring in the bypass valve and loosen it up alot. Originally I think it's supposed to open at -6psi but now it's really loose and does take much less vacuum to open. Although this didn't help. Actually I don't think it's the bypass valve that's causing the problem. Because as long there is over pressure in the manifold, that pressure will keep the bypass valve shut.
I checked the throttle positioning with an odb interface in my phone. Although closed throttle is around 16% open and full throttle is about 79% open according to it, the tps sensor seems to be the same and follow the gas pedal the same with the charger on as without. (Probably)Ruling out that the boost pressure forces the throttle to open more.
Btw, the vacuum hoses I firstly used where to weak so I'm using fuel hoses now instead.
Some pictures of how he bypass valve is connected.
https://dl.dropboxusercontent.com/u/1153....10.55.jpg
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![[Image: FB_IMG_1474048273787_zpsnbfq6a3s.jpg]](http://i1227.photobucket.com/albums/ee440/davis5835/Mobile%20Uploads/FB_IMG_1474048273787_zpsnbfq6a3s.jpg)
Altough the problem is still there, it rarely happens now. It occurs when the engine is running a steady rpm just around 0 vacuum. The load just slightly increases and it starts to recieve some boost. If I then just hold the same throttle position or just very gently release it a tiny bit so the vacuum should return again, it sometimes continues to boost. If nothing then changes (throttle/load) this will trigger the "fail" mode.
Btw. When it happens the compressor starts sounding a bit wierd, like it's building pressure against a wall.
Just out of curiosity, has anyone else experienced this problem?
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Oh, so that's what that was.. Thanks alot Lexuspat! Now it works alot better.
Altough the problem is still there, it rarely happens now. It occurs when the engine is running a steady rpm just around 0 vacuum. The load just slightly increases and it starts to recieve some boost. If I then just hold the same throttle position or just very gently release it a tiny bit so the vacuum should return again, it sometimes continues to boost. If nothing then changes (throttle/load) this will trigger the "fail" mode.
Btw. When it happens the compressor starts sounding a bit wierd, like it's building pressure against a wall.
Just out of curiosity, has anyone else experienced this problem?
Skickat från min E5823 via Tapatalk
![[Image: LexuS-Copy.jpg]](http://i65.photobucket.com/albums/h204/Sparkystav/LexuS-Copy.jpg)
Read my thread here: The Evolution of my Turbo Lexus from NA-Supercharged-Twin Turbo-Massive Single
Please leave your comments.
Sparkystav
02-07-2023, 10:42 PM #4That could be a symptom of the is200 electronic throttle. Remember movement of the pedal doesn't necessarily mean movement of the throttle.
Read my thread here: The Evolution of my Turbo Lexus from NA-Supercharged-Twin Turbo-Massive Single
Please leave your comments.
Supercharge it they said, it'll be fun they said
👍(Wasnt over revving either, altough it happend around 5500 - 6000 rpm in last gear) wss
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Well that joy didn't last for long. 2 days with the compressor on and working and threw a rod today. Havn't confirmed it yet as it's late and dark outside atm, but at the looks of it the engine block got pierced good.
Supercharge it they said, it'll be fun they said 👍
(Wasnt over revving either, altough it happend around 5500 - 6000 rpm in last gear) wss
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