BOV staying open at idol
#1
BOV staying open at idol
well im trying to figure out why my BOV is staying open at idol. i have been trying to do some research and the only thing i can come up with is that i need a different spring. but i would thing zzp would have gave me the right spring for what i need. i am going to check what spring i have this evening. i was also looking at the charts for tial springs and my car idols the vac is at -20 and according to tial that would be the pink spring. on the zzp web site they show i believe only the white spring and the unpainted spring. im confused. someone please help me out
#5
Senior Member
If you have high idle, you probably have a vacuum leak. Go get a can of brake cleaner and spray around all the different connections. IM to head, IM to TB, TB to charge piping, etc. Get all the couplers. You'll know you found the leak when you spray it, trust me...
Last edited by Edubs; 06-24-2011 at 10:42 AM.
#10
well i fixed every leak i could possibly find and found an oil leak for the return oil line on the turbo. i guess tomorrow ill take that off and put some of that black gasket stuff on it and see what happens. bov is still staying open at idle. still cant figure out why
#13
sorry man its been a long day. i have all kinds of people telling me a blow off valve should be closed at idle and people telling me it should stay open and vent at idle. its pretty confusing when this is my first turbo and im learning from this. i have been making sure all my vac lines are tight because my car wants to idle anywhere from 1200 to 1500 rpms. i was told this could be causing this problem. i also took out my fuel injectors and replaced the rings and cleaned everything and greased everything like i was told to do and it seemed to help out alittle but not by much
#14
Senior Member
Do you have HPT or an interceptor? Something to monitor STFT and LTFT?
Did you test for leaks everywhere else between the turbo and intake manifold?
What did ZZP say when you asked them about the BOV?
EDIT:
Alright, I looked into it more. I run a BPV as opposed to a BOV, so I get a little confused time to time.
Your BOV should be closed at idle and should have a spring that holds the valve closed until just a hair more vacuum than your engine makes at idle. Basically, if your engine is 19hg at idle, you should have a 20-21hg spring in there. That way at idle, the spring will be able to keep in closed, but when you let off the throttle in boost, the boost pressure pressing on the other side, in combination w/ the vacuum pulling from the source, will easily open the valve and allow the pressure to be bled off. If it opens at idle, you are letting off metered air to atmosphere. This can cause your idle issues...
Did you test for leaks everywhere else between the turbo and intake manifold?
What did ZZP say when you asked them about the BOV?
EDIT:
Alright, I looked into it more. I run a BPV as opposed to a BOV, so I get a little confused time to time.
Your BOV should be closed at idle and should have a spring that holds the valve closed until just a hair more vacuum than your engine makes at idle. Basically, if your engine is 19hg at idle, you should have a 20-21hg spring in there. That way at idle, the spring will be able to keep in closed, but when you let off the throttle in boost, the boost pressure pressing on the other side, in combination w/ the vacuum pulling from the source, will easily open the valve and allow the pressure to be bled off. If it opens at idle, you are letting off metered air to atmosphere. This can cause your idle issues...
Last edited by Edubs; 06-23-2011 at 11:05 PM.
#15
Do you have HPT or an interceptor? Something to monitor STFT and LTFT?
Did you test for leaks everywhere else between the turbo and intake manifold?
What did ZZP say when you asked them about the BOV?
EDIT:
Alright, I looked into it more. I run a BPV as opposed to a BOV, so I get a little confused time to time.
Your BOV should be closed at idle and should have a spring that holds the valve closed until just a hair more vacuum than your engine makes at idle. Basically, if your engine is 19hg at idle, you should have a 20-21hg spring in there. That way at idle, the spring will be able to keep in closed, but when you let off the throttle in boost, the boost pressure pressing on the other side, in combination w/ the vacuum pulling from the source, will easily open the valve and allow the pressure to be bled off. If it opens at idle, you are letting off metered air to atmosphere. This can cause your idle issues...
Did you test for leaks everywhere else between the turbo and intake manifold?
What did ZZP say when you asked them about the BOV?
EDIT:
Alright, I looked into it more. I run a BPV as opposed to a BOV, so I get a little confused time to time.
Your BOV should be closed at idle and should have a spring that holds the valve closed until just a hair more vacuum than your engine makes at idle. Basically, if your engine is 19hg at idle, you should have a 20-21hg spring in there. That way at idle, the spring will be able to keep in closed, but when you let off the throttle in boost, the boost pressure pressing on the other side, in combination w/ the vacuum pulling from the source, will easily open the valve and allow the pressure to be bled off. If it opens at idle, you are letting off metered air to atmosphere. This can cause your idle issues...
and yes i did, i dont have a boost leak tester but i used brake cleaner and could not find anything.
i do get what you are saying about the spring now. thank you i talked to ryan and i did all the steps he told me to do and it helped out cause the idle isnt as bad but its still up there around 1200 rpms. he said he thinks he put a 10 pound spring in the bov which i looked on tial web site and it is for -16 to -19hg. my car is idling at -20. i dont know if it is doing this cause i still have some kind of leak somewhere. tomorrow i dont have to work so i am gonna be all over this car and on here alot. lol
#16
Senior Member
he said he thinks he put a 10 pound spring in the bov which i looked on tial web site and it is for -16 to -19hg. my car is idling at -20. i dont know if it is doing this cause i still have some kind of leak somewhere. tomorrow i dont have to work so i am gonna be all over this car and on here alot. lol
#17
your bov should be 100% closed at idle. only a recirculating valve is open at idle. if your bov is open at idle then your creating lag because of boost leakage. if your idle vacuum is 20inhg at idle in gear(if auto) then you will need a spring that is just over 20"hg. when your boosting and then you close the throttle the vacuum will spike higher than your idle vacuum and that is the only time you want the bov to open. i usually shitcan the non adjustable type bov's and get the adjustable ones just because of this type of problem.
#19
Senior Member
I'm assuming you are saying that you took out a white spring and ordered an unpainted spring to put in? If so, that should solve your problem...
Good luck and let us know how you make out!
Good luck and let us know how you make out!
#21
i have tried everything i can possibly think of to find any leaks. i would make a boost leak tester but our lows got hit by a tornado so i have no way of getting a coupling unless i wanna drive 30 miles to the next hardware store
#22
Senior Member
You may want to try shims. The Pink spring is for 22-23hg, which your car isn't pulling. It may be too strong to function properly. I guess we'll see. Just be careful and watch out for compressor surge if the valve doesn't open w/ the heavier spring...
#24
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x2. See if they got shims
#25
also i tried something new. when i disconnected the vac line that goes to the bottom of my waste gate the blow off valve closed. is there something that could cause that?