Why's my car only pushing 5 pounds boost?

[LextownGST]

Hey guys...I just bought a 1998 GS-T and for some reason its only pushing 5 pounds of boost when it is supposed to be pushing 12 pounds stock...I have no idea why it is doing this. Any ideas on what might be causing this or what I need to do? and an FYI I'm a girl so don't make fun of me cuz I don't know this shit... at least I'm trying to learn!

 

[Lunch_Box]

Check for boost leaks.

 

[LextownGST]

where would you check for boost leaks at? do you think its my boost controller?

 

[LextownGST]

At idle or cruise when i left off the gas it only has 2 psi of vacuum on my gauge, is maybe the boost gauge off or , possible bypass valve? All I have is an intake and thought maybe they hooked it up wrong, I have no boost controller sorry for the mistype. All stuck except intake.

 

[Ultimatedsm]

Make a boost leak tester. Just search it on the DSMTUNERS and you will find many links. Once you make the tester, put some soapy water on your pipes and pump about 30 psi into the intake tract. I would recommend an air compressor, or go to a gas station and use there tire pump. Check if your BOV line didn't pop off either.

 

[Absolutegtr]

Check to make sure that the silicone coupler things are tight and are not cracked, also make sure that there are no holes in the piping...Good luck!

 

[machv83]

check to see if your bov line poped off if it poped off u will only have 5 psi of boost instead if 12 psi

 

[kronix0420]

are you still using the stock boost guage?? if so find a "mechanical boost guage" to use and see if its just the guage, if not do what the others before me told you to do

 

[LextownGST]

cheap e-bay boost gauge....thats why I thought it might be off

 

[Ultimatedsm]

check to see if your bov line poped off if it poped off u will only have 5 psi of boost instead if 12 psi

I already said this in my post.

LextownGST cheap e-bay boost gauge....thats why I thought it might be off

You buy cheap you get cheap. I don't trust ebay too much, only if I know they are selling quality name brand parts. Go get an autometer boost gauge, they are not very expensive, around $40-60 depending (Budget ones of course).

If your car isn't performing properly, and your car runs like crap (doesn't move when boost hits) than you have a boost leak. There are drivebility issues with boost leaks, so if you don't have any, it could be your boost gauge thats off. This has happend to me before, it is very possible.

 

[TooFastTooG]

When I installed my autometer boost gauge, I was running 12 stock. On my way home a day later I was driving down the road and noticed I was only pushing 5psi . Car felt the same, so I popped my hood and it turned out the vac line was almost off my T fitting, got a better T fitting and went right back to 12 psi

The biggest question that is going to helps us, like stated above, is how does your car drive? If it "feels" fine to you then most likley its the shitty gauge you bought. If it feels weak then you have leaks somewhere.

 

[a_scobel]

http://vfaq.com/mods/ICtester.html

 

[LextownGST]

well when i bought this car it already had the shitty boost gauge so I can't really do anything bout that.....that could be it or it might be the vacuum line.....its driving me nuts thou!!

 

[ltho98]

To me sounds more like a clogged catalytic converter. Drop your downpipe and you'll find out if its that right away.

 

[ddavisaf]

To me sounds more like a clogged catalytic converter. Drop your downpipe and you'll find out if its that right away.

No, it's a boost leak. Run a boost leak test. 20 psi steady for 30 seconds or more. Start at the TB Elbow, then LICP, then turbo inlet.

 

[Ultimatedsm]

Check this out:

http://members.shaw.ca/dsm.1000q/Engineprimer/2G/throttlebody.htm


If you have no drivability issues, your boost gauge is properly screwed up or connected wrong. If you think your car is lagging, than you have a boost leak problem. BOOST LEAK TEST! Like oldman would say .

 

[Ultimatedsm]

Please do the checks and tests before you post again. Problems are not fixed by just posting and posting. This is a bad habit to get into. Anyway, I hope all the information provided by the dsmer's help you out. Good luck with your car

 

[Ultimatedsm]

At idle or cruise when i left off the gas it only has 2 psi of vacuum on my gauge, is maybe the boost gauge off or , possible bypass valve? All I have is an intake and thought maybe they hooked it up wrong, I have no boost controller sorry for the mistype. All stuck except intake.

It is actually 2 inches of mercury . Just want to correct you for next time. When the gauge goes opposite to the boost pressure, it is called vacuum which is measured in HG or inches of mercury. If your car is idling well and your gauge reads 2 HG on deceleration or idle, it is your gauge. On deceleration, you should read around 22-24HG and on idle should be around 17-19 HG.

 

[ltho98]

If she had a boost leak that was massive enough to leak it to 5psi, there would be other issues like the MAS counting more air than is actually in the charged system and running really effing rich. Even with a decent sized boost leak due to a blown coupler, i achieved 10psi of boost but because it was running so crappy it would break up and misfire.

Thats why I say, catalytic converter restricting the exhaust side. Possible pre-turbo exhaust leak as well.

Or.. dead turbo. or... crappy gauge.

 

[WCDSM]

Checking the catalytic converter can't hurt, that happened to my car, my cat got smashed and my boost went from 15, to 12, to 5, to non existent. Besides its faster to check your cat then it is to do a boost leak test.

 

[Boostedexcel]

you could also check check the cat by looking at your vacumn readings-if you have barely any vacumn then there is a good chance your cat is clogged. i recommend a VDO gauge, I think autometer is crap! But it doesnt really sound like your cat would be causing this...how about a stuck open waste gate or a bad map sensor or just a crapy boost gauge...check the fitting on the back of the gauge and make the sure the line is in there good.

 

[Yoshi]

i know how u feel some thing kinda happend to me... check and see if the wastegate solinoid is connected properly and nothing came loose or undone that happend to me and i was pushing about 8 psi the i hooked it back up and it was back up to 12-14