Very low boost

[highvan]

I just hooked up a faze boost gauge, it's showing 20-21 in the vac at idle, but it's only showing between 3-5 psi when i get on it... The car has 235,000miles on it, but to drive it and look at it you could never tell. also, before i hooked up the gauge, i would go by the stock one on the dash and sometimes it would read around 7-9psi on most days and other times it would read 12-14psi? Is there anything i can do to get my boost up or is there a problem with my turbo or something? I just ordered a manual boost controller yesterday.. any help, info or tips would be great, thanks B

 

[president95]

Have you done a boostleak test to check for any leaks?
http://www.dsmtuners.com/forums/showthread.php?t=169435
Make sure to spray soapy water so you can see the leaks,they'll bubble. Dont just listen for them.

 

[president95]

There are also DIY boostleak testers too btw.

 

[highvan]

Where all should i spray the soapy water?

 

[RyanJ]

originally posted by: Travislaw
Start at the throttle body elbow, check for leaks in injectors seals, PCV, throttle BISS screw, throttle shaft O-Rings, and vaccum lines. Then once any leaks found are taken care of, test at the Intercooler on the intake side. Again look for intercooler leaking, connections leaking, the BOV gasket leaking. Then test at the turbo. Check for connection leaks, a well known one is the J-Pipe where the J-Pipe meets the turbo.

Also the stock boost gauge is crap. I wouldn't put any stock in its readings. Also check your turbo for shaft play if you think it might just be that.

 

[highvan]

Well, I did the old soapy water trick, showed now bubbles that i could see, i even took all the hoses off and red tightned them and i even took the can off of my intake. I did a test run, still only showing around 2-4psi on my faze gauge??? This is my first turbo car and i've only had it about a week, so i'm not really sure what else i can do. I ordered a manual boost controller, but will that help? I'm not even sure how to check my turbo for shaft play and or how to fix that if it is and help would be great, thanks, B

 

[RyanJ]

Remove the intake hose off of the turbo inlet, make sure the car hasn't been running in awhile. Turbos get hot. grab the shaft with you fingers and wiggle it. Alittle side to side, up and down is ok, but only alittle. In and out is bad bad bad.

 

[oldman]

Well, I did the old soapy water trick, showed now bubbles that i could see, i even took all the hoses off and red tightned them and i even took the can off of my intake. I did a test run, still only showing around 2-4psi on my faze gauge??? This is my first turbo car and i've only had it about a week, so i'm not really sure what else i can do. I ordered a manual boost controller, but will that help? I'm not even sure how to check my turbo for shaft play and or how to fix that if it is and help would be great, thanks, B

did you just spray soapy water while the engine is on? Soapy water test will only work during a boost leak test when the intake tract is pressurized.

Also, where are you tapping the boost gauge into? What does the boost gauge read with the car off?

 

[RyanJ]

Originally postedldman
did you just spray soapy water while the engine is on? Soapy water test will only work during a boost leak test when the intake tract is pressurized.

haha good point.

 

[highvan]

yeah, i just had the car running when i sprayed it Remember, i'm new to all this I tapped it into the fuel pressure control solenoid, at idle it shows 20-21 in the vac and when the car is off, it shows it at 0

 

[oldman]

I tapped it into the fuel pressure control solenoid, at idle it shows 20-21 in the vac and when the car is off, it shows it at 0

Then the Gauge is probably good, this is what you should look into.

1. Re-do the soapy water test while performing a boost leak test.

2. Check for exhaust leaks before turbo.

3. Remove the actuator arm and make sure the wastegate flapper is properly closing.

4. Check the turbo for shaftplay like already suggested.

 

[president95]

yeah, i just had the car running when i sprayed it

Woops, I'll try to be more specific next time.

 

[highvan]

well, i just checked the turbo for shaft play, very stif. where is the actuator arm and wastegate flapper? is that the thing connected to the bottom of the turbo?

 

[oldman]

well, i just checked the turbo for shaft play, very stif. where is the actuator arm and wastegate flapper? is that the thing connected to the bottom of the turbo?

I have already given you clear directions and it's time for you to search on your own, the best way to learn is through search and read. You can still post follow up questions here after you search but at least it will be a more informative one.

 

[RyanJ]

Originally posted:Oldman
the best way to learn is through search and read.

Just a tip when searching use the adavanced search and search titles only. If you haven't noticed I'm n/t. All the answers I gave you were the result of a 5 second search.

Edit:added quote

 

[Newlogics]

still, just to eliminate a possibility of a faulty gauge (see some cases before, needle just gets caught on something), try another one, or get a manual pressure pump with a gauge, and cross-reference the pressure reading.

 

[highvan]

Thanks for the help on this one everyone. I believe i figured out the problem, the actuator arm for the wastegate, came off. I believe there must of been some type of pin there that held it on, i'll have to pick something up from autozone tomorrow, but she is showing 10-11psi now

 

[oldman]

Good job.