Not building boost - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

mRclARK1 · 07-31-2006, 04:54 PM

My SR won't build any boost whatsoever...and I can't seem to find a leak anywhere. Also, my boost controller (I don't have a boost gauge yet.

) is reading all over the place under acceleration. I'm reading about -9 psi of vacuum (about 18 mmHG correct?...sorry can't remember how to convert it) at idle. Under acceleration it starts to build boost, but when it gets around -6 psi or so it stops increasing but will read all over the place from -4psi to -9psi...it just won't build any boost. Any suggestions of possible causes or culprits...I'll keep looking for a boost leak; but I haven't found one yet and I've tightend up and checked all my IC piping and vac lines...hasn't made a difference. Thanks in advance!

Turbo setup is: Redtop SR (T25)
FMIC
Blitz BOV
Greddy PRofec B Spec II

*NemeGuero* · 07-31-2006, 04:57 PM

Do the pressure tester on your IC piping.

And also, are you using stock wastegate? Sounds like the actuator is all fuct.

mRclARK1 · 07-31-2006, 05:10 PM

Yeah, it's the stock actuator/wastegate. I checked it out before I started up the car and it seemed to be working fine. I can hear it open when I apply vacuum to it, and I can open it by hand...so I don't think it's seized. But I'll give it another check.

mRclARK1 · 07-31-2006, 10:06 PM

Well I took it out for a drive again, after tightening up IC piping etc. again...and it's still doing it. But it's getting better. I am building up some boost now. So I must just have a leak somewhere I missed...I'll post again if I can't find anything after another good check.

nsn240 · 08-01-2006, 12:10 AM

Quote:

Originally Posted by mRclARK1

Well I took it out for a drive again, after tightening up IC piping etc. again...and it's still doing it. But it's getting better. I am building up some boost now. So I must just have a leak somewhere I missed...I'll post again if I can't find anything after another good check.

an easier way to find those leaks... run to home depot find some pvc pluming with a cap, epoxy a valve stem from an old bike tire in the end and tighten it with one of the couplers... pump it up to 15-20psi and listen for leaks

*NemeGuero* · 08-01-2006, 02:25 AM

Yah, even if you don't think you have a leak.. DO THE TESTER ^^
thats how I found my leak..

mRclARK1 · 08-01-2006, 06:52 PM

Yeah...I've been meaning to do it anyway. Especially now since I'm having problems; I'll get it done ASAP. Thanks guys.

bongnak · 08-02-2006, 12:15 AM

how about the bov is it leaking/stucking you think. try capping off the bov somehow or using someone elses.

fico · 08-02-2006, 12:28 AM

All I know.... boost controller + no boost gauge = BADDDDD

*NemeGuero* · 08-02-2006, 02:38 AM

Quote:

Originally Posted by fico

All I know.... boost controller + no boost gauge = BADDDDD

Why? I don't agree.

mRclARK1 · 08-02-2006, 05:16 PM

Quote:

All I know.... boost controller + no boost gauge = BADDDDD

I'm using a Greddy profec B specII...it reads boost/vacuum while you drive. So it IS a boost gauge as well...I just want a mechanical one to make sure I have correct readings...and have it in an easier to see spot.

I still gotta do the pressure testing on my IC piping, and I fiddled with the boost controller settings a bit, that improved it as well. I guess it just needed some fine tuning from my previous settings. And I may still have a leak somewhere...I'm gonna check ASAP.

07-31-2006, 04:54 PM	#1
mRclARK1 Post Whore! Join Date: Sep 2005 Location: Location? Posts: 4,205 Trader Rating: (0) Feedback Score: 0 reviews	Not building boost My SR won't build any boost whatsoever...and I can't seem to find a leak anywhere. Also, my boost controller (I don't have a boost gauge yet. ) is reading all over the place under acceleration. I'm reading about -9 psi of vacuum (about 18 mmHG correct?...sorry can't remember how to convert it) at idle. Under acceleration it starts to build boost, but when it gets around -6 psi or so it stops increasing but will read all over the place from -4psi to -9psi...it just won't build any boost. Any suggestions of possible causes or culprits...I'll keep looking for a boost leak; but I haven't found one yet and I've tightend up and checked all my IC piping and vac lines...hasn't made a difference. Thanks in advance! Turbo setup is: Redtop SR (T25) FMIC Blitz BOV Greddy PRofec B Spec II

07-31-2006, 04:57 PM	#2
NemeGuero No more nissan. Join Date: Jan 2003 Location: RAIN, Washington. Age: 40 Posts: 8,132 Trader Rating: (10) Rides Gallery: NemeGuero Feedback Score: 10 reviews	Do the pressure tester on your IC piping. And also, are you using stock wastegate? Sounds like the actuator is all fuct. __________________

08-01-2006, 02:25 AM	#6
NemeGuero No more nissan. Join Date: Jan 2003 Location: RAIN, Washington. Age: 40 Posts: 8,132 Trader Rating: (10) Rides Gallery: NemeGuero Feedback Score: 10 reviews	Yah, even if you don't think you have a leak.. DO THE TESTER ^^ thats how I found my leak.. __________________

08-02-2006, 12:15 AM	#8
bongnak Zilvia Junkie Join Date: Jan 2005 Location: So-Cal Age: 41 Posts: 337 Trader Rating: (3) Feedback Score: 3 reviews	how about the bov is it leaking/stucking you think. try capping off the bov somehow or using someone elses. __________________ Zzzz

07-31-2006, 05:10 PM	#3
mRclARK1 Post Whore! Join Date: Sep 2005 Location: Location? Posts: 4,205 Trader Rating: (0) Feedback Score: 0 reviews	Yeah, it's the stock actuator/wastegate. I checked it out before I started up the car and it seemed to be working fine. I can hear it open when I apply vacuum to it, and I can open it by hand...so I don't think it's seized. But I'll give it another check.

07-31-2006, 10:06 PM	#4
mRclARK1 Post Whore! Join Date: Sep 2005 Location: Location? Posts: 4,205 Trader Rating: (0) Feedback Score: 0 reviews	Well I took it out for a drive again, after tightening up IC piping etc. again...and it's still doing it. But it's getting better. I am building up some boost now. So I must just have a leak somewhere I missed...I'll post again if I can't find anything after another good check.

08-01-2006, 06:52 PM	#7
mRclARK1 Post Whore! Join Date: Sep 2005 Location: Location? Posts: 4,205 Trader Rating: (0) Feedback Score: 0 reviews	Yeah...I've been meaning to do it anyway. Especially now since I'm having problems; I'll get it done ASAP. Thanks guys.

08-02-2006, 12:28 AM	#9
fico Leaky Injector Join Date: Jul 2006 Location: Akron Ohio Age: 37 Posts: 119 Trader Rating: (0) Feedback Score: 0 reviews	All I know.... boost controller + no boost gauge = BADDDDD