weird boosting?

supraluver4life · 02-04-2010, 10:21 PM

so my car used to be running around 8-10 psi and on the stock boost gauge, as soon as it would boost the needle would jump to eight. now it feels as though ive lost like 40 hp and the needle only goes up to 4 psi. im going to install my aftermaket boost gauge and see what its really going to. any reason it would do this? it just feels like its not boosting all the way

Green7mgte · 02-04-2010, 11:03 PM

boost leak.

supraluver4life · 02-05-2010, 12:35 AM

so how do i find the leak?

Green7mgte · 02-05-2010, 01:04 AM

I think i was a bit hasty to post. saying you lost some boost is another story. a boost leak will generally allow you to boost to your set goal depending on the severity of the leak. but will start to drop off once the goal is reached. dropping 4psi of boost overnight is a different concern. i would still check for leaks. check your piping and reconnect anything loose.
a boost down tester will generally cost about 20 dollars for the gauge. install it and pump compressed air into it. then check for hiss's. fill a spray bottle with soapy water and check for bubbles on all hoses that hold boost.
I would also check the usual suspects. clogged intake/exhaust. and a worst case scenario just to scare you is your turbo is nearing failure and your MAP ecu is cutting fuel to save it. just kidding (it's real but probably doesn't pertain to you.) I would check for leaks around your gasket and valves. run a compression test. check problems with pcv valve and BPV. Im just thinking out loud basically.

here read this
http://www.fd3s.net/boost_problems.html looked like it had allot of good information in it.

supradaddy0803 · 02-05-2010, 02:51 AM

Second on that!!!!! I would say easy stuff first then move to the stuff that will cost you money.

cre · 02-06-2010, 07:41 PM

Boost leak, exhaust leak (preturbo), blown BOV or a stuck wastegate.

Green7mgte · 02-06-2010, 11:07 PM

i mentioned exhaust leak before turbo in the original post. but a loss of 4psi would be one hell of an exhaust leak. and you would definitely see the exhaust coming up from behind the motor. so i ruled it out and deleted it from the post. still a possibility tho id imagine

cre · 02-07-2010, 12:00 AM

Quote:

Originally Posted by Green7mgte

a loss of 4psi would be one hell of an exhaust leak. and you would definitely see the exhaust coming up from behind the motor.

Yes, it would and no you wouldn't... it'd be big enough that if you knew the difference you'd hear it, but you wouldn't necessarily see anything as the leak wouldn't be losing a large volume of gasses until a high load.

Green7mgte · 02-07-2010, 12:03 AM

Quote:

Originally Posted by cre

Yes, it would and no you wouldn't... it'd be big enough that if you knew the difference you'd hear it, but you wouldn't necessarily see anything as the leak wouldn't be losing a large volume of gasses until a high load.

I have a small exhaust leak. smokes a tad at start up.

supraluver4life · 02-08-2010, 12:59 AM

haha so um... how to put this...

my turbo blew... i think. well i go too accelerate, and there is a terrible whining sound coming from somewhere around the turbo. really loud and it just gets under your skin. it will boost though if you tough through the wining and when it does boost the noise goes away so someone should confirm that it is in fact a blow turbo.

oh and what kinda shaft play should i look for?

02-04-2010, 10:21 PM	#1
supraluver4life 3" Exhaust Join Date: Nov 2009 Location: Santa Fe, NM Posts: 135	weird boosting? so my car used to be running around 8-10 psi and on the stock boost gauge, as soon as it would boost the needle would jump to eight. now it feels as though ive lost like 40 hp and the needle only goes up to 4 psi. im going to install my aftermaket boost gauge and see what its really going to. any reason it would do this? it just feels like its not boosting all the way __________________ Cusco front, Tein Rear coilovers Massive DDP, 3'' custom catless exhaust, Tsudo muffler 4.5'' outlet, Apexi cold air intake, Act stage 3 clutch, ct26 turbo (stock)- 10psi +300rwhp "Not driving a car because its too nice, is like not fucking your gf so shes still tight for the next guy"

02-04-2010, 11:03 PM	#2
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	boost leak. __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines : Last edited by Green7mgte; 02-05-2010 at 03:42 AM. Reason: eddited. exhaust leak dosn't fit this.

02-05-2010, 12:35 AM	#3
supraluver4life 3" Exhaust Join Date: Nov 2009 Location: Santa Fe, NM Posts: 135	so how do i find the leak? __________________ Cusco front, Tein Rear coilovers Massive DDP, 3'' custom catless exhaust, Tsudo muffler 4.5'' outlet, Apexi cold air intake, Act stage 3 clutch, ct26 turbo (stock)- 10psi +300rwhp "Not driving a car because its too nice, is like not fucking your gf so shes still tight for the next guy"

02-05-2010, 01:04 AM	#4
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	I think i was a bit hasty to post. saying you lost some boost is another story. a boost leak will generally allow you to boost to your set goal depending on the severity of the leak. but will start to drop off once the goal is reached. dropping 4psi of boost overnight is a different concern. i would still check for leaks. check your piping and reconnect anything loose. a boost down tester will generally cost about 20 dollars for the gauge. install it and pump compressed air into it. then check for hiss's. fill a spray bottle with soapy water and check for bubbles on all hoses that hold boost. I would also check the usual suspects. clogged intake/exhaust. and a worst case scenario just to scare you is your turbo is nearing failure and your MAP ecu is cutting fuel to save it. just kidding (it's real but probably doesn't pertain to you.) I would check for leaks around your gasket and valves. run a compression test. check problems with pcv valve and BPV. Im just thinking out loud basically. here read this http://www.fd3s.net/boost_problems.html looked like it had allot of good information in it. __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines :

02-05-2010, 02:51 AM	#5
supradaddy0803 12psi boost Join Date: May 2006 Location: Athens, TX Posts: 308	Second on that!!!!! I would say easy stuff first then move to the stuff that will cost you money. __________________ 1987 supra NA 5 speed 1JZGTE swap Tokico Illumina 2 and Eibach springs Tokico pillow blocks Suspension Techniques front and rear sway bar HKS super dragger cat-back exhaust plus test pipe Greddy Profec B spec 2 boost controller HKS type 1 turbo timer Supra sport solid steel drive shaft Walboro 255 fuel pump JZA70 Front end mod 18" Volk Racing AV3 18x8.5 front 18x9.5 rear

02-06-2010, 07:41 PM	#6
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Boost leak, exhaust leak (preturbo), blown BOV or a stuck wastegate. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

02-06-2010, 11:07 PM	#7
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	i mentioned exhaust leak before turbo in the original post. but a loss of 4psi would be one hell of an exhaust leak. and you would definitely see the exhaust coming up from behind the motor. so i ruled it out and deleted it from the post. still a possibility tho id imagine __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines :

02-08-2010, 12:59 AM	#10
supraluver4life 3" Exhaust Join Date: Nov 2009 Location: Santa Fe, NM Posts: 135	haha so um... how to put this... my turbo blew... i think. well i go too accelerate, and there is a terrible whining sound coming from somewhere around the turbo. really loud and it just gets under your skin. it will boost though if you tough through the wining and when it does boost the noise goes away so someone should confirm that it is in fact a blow turbo. oh and what kinda shaft play should i look for? __________________ Cusco front, Tein Rear coilovers Massive DDP, 3'' custom catless exhaust, Tsudo muffler 4.5'' outlet, Apexi cold air intake, Act stage 3 clutch, ct26 turbo (stock)- 10psi +300rwhp "Not driving a car because its too nice, is like not fucking your gf so shes still tight for the next guy"

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