turbo no boost

[JStoked]

Finally got everything put back together after replacing a couple of bad injectors. Started it up, and i couldn't have been happier....
but I don't seem to be getting any boost. vac at idle is about -2, which seems about right. when I rev it up, gauge goes to -4 (max), and never goes up. It won't go into positive.
I checked the turbo, when it runs (without the intake piping on), the turbine spins, so i know it's not locked up, or something. I "tested" the pressure sensor, by blowing into it, and I was able to get it to show to 8psi (maxed it out). if i varied how hard I blew, the gauge did go up and down (no, homo).
checked, and double checked all the vacuum and intake lines, no leaks anywhere.
any idea why I am not getting any pressure?
not sure what else I need to check...

 

[SupraSean]

have you actually drove the car? or just free revs? you generally wont build much boost if any at all from a free rev. plus stock boost gauge is pretty much useless.

 

[JStoked]

Yes, I drove the car; not wot down the freeway, but enough where it should have built some boost.
I recently helped boostEd90 get his 7m running, and we could hear the turbo spool up (even a free rev). not getting that from mine.

 

[SupraSean]

Check intake piping, hoses etc. does it FeEl like its spooling?

 

[JStoked]

ok put a new turbo on ( the old one locked up) put all back togeather. still no boost. could this be a bad blow off valve? It is still going in to the negative on the gauge. Or could my intercooler be bad?

 

[bioskyline]

is the wastegate working properly??

 

[Inygknok]

Finally got everything put back together after replacing a couple of bad injectors. Started it up, and i couldn't have been happier....
but I don't seem to be getting any boost. vac at idle is about -2, which seems about right. when I rev it up, gauge goes to -4 (max), and never goes up. It won't go into positive.
I checked the turbo, when it runs (without the intake piping on), the turbine spins, so i know it's not locked up, or something. I "tested" the pressure sensor, by blowing into it, and I was able to get it to show to 8psi (maxed it out). if i varied how hard I blew, the gauge did go up and down (no, homo).
checked, and double checked all the vacuum and intake lines, no leaks anywhere.
any idea why I am not getting any pressure?
not sure what else I need to check...

Hhehehehe.... really shouldn't have said anything. Now it does sound homo


Seriously now. If you swapped turbos and it still didn't show any pressure, then it's not the turbo itself unless you're really shit out of luck and they both have stuck open wastegates; even then it should read at least 1 psi under wot I believe. Even with a minor leak, it should read something. Are you sure the gauge is hooked up correctly? Is it an aftermarket gauge or the stock one in the cluster?

 

[paradox616]

First up stop guessing that'll get you no where quick. Facts: Your turbo has seized once, You cannot build boost, the factory gauge does not measure in PSI (well AUS delivered ones don't anyway, not %100 sure about USA but i doubt it.)

When trying to build boost (in gear) are there any abnormal noises?

1) your turbo was ok then it seized? why did it seize? has it got oil pressure?
2) When replacing your turbo did you make sure all the intercooler piping is sealed? if there is a big enough leak you wont see any positive pressure, Did you prime the turbo before installation?
3) you can block off the vacuum hose to the blow off valve to test it.
4) check codes!!!!!!!!!!!!!!!!!!!!!
5)When trying to boost do you notice any black smoke out the exhaust and/or does it run rough?


Id be testing the intercooler piping for leaks, This can be done with some pvc caps, a air compressor and some silicon joiners.

 

[JStoked]

I don't think it's the waste gate I have seen the turbo
work it was on a friends car and he upgraded. And the
Reason the old turbo locked up was because the idiot before
Me rtvd all the gaskets on and clogged the oil feed line up
So I'm hopeing it's the ic piping.

 

[D.J.T.]

you have to actually drive the car on the freeway.. GO FOR IT TRUST ME.. My gauge at idle is at -4 psi & doesn't move at all until the turbo starts boosting. Im running in gear at about 2800 rpms & then floor it some & shoots up to 0 psi & then keeps going up. But like normal driving around town without stepping on it, the boost gauge doesn't move. When im getting on the freeway it moves clearly. & yes check out IC Piping leaks & IC leaks too.

 

[JStoked]

Ok got home and got to playing around with it and it is boosting. Just the something is wrong with the stock gauge.

 

[D.J.T.]

Ok got home and got to playing around with it and it is boosting. Just the something is wrong with the stock gauge.

If you say you tried putting air into the boost sensor & the gauge moved then the problem is not the gauge. Probably the line that goes to the sensor is clogged or its not properly connected. Is this a completely stock setup? & it might be that white box behind the cluster, because the GAUGE is moving after all

 

[JStoked]

Yes it's a stock set up. The car is boosting
it's just the gauge goes to -4 no matter how
hard I drive it at idle it sets at 0 like it is suppose
to.

 

[D.J.T.]

Yes it's a stock set up. The car is boosting
it's just the gauge goes to -4 no matter how
hard I drive it at idle it sets at 0 like it is suppose
to.

Odd. Maybe its the white box screwed into the cluster. You should take a picture of the pressure sensor & where it connects to so we can see how its connected. & not sure about 0 being correct but if it is i need it confirmed, show me the thread :] My gauge always idles at -4 when it starts boosting it shoots up quickly to 0 or 4 & keeps going up depending how much its boosting. ill post a pic of my vacuum lines to the pressure sensor soon. its going to be sitting in the garage for a while anyways. clutch slip makes it barely driveable. :/ & yes im running stock set up as well

 

[D.J.T.]

Ok here are some photos i took a couple mins ago. the one with the red arrow means that hose goes to the intake manifold. from the intake it goes to a T. on the right of the T it goes to what looks like a TT & so on. & I had gloves on because it is still hot. yep

 

[JStoked]

cool thank you so much. i had mine hooked up wrong. gauge is now working properly but my idle is around a grand( don't think that is right) cps adjustment i hope and i have a vac leak somewhere. almost there!! this car sat in a field for over five years before i got it so im just trying to get it back to right. thank you for your help.

 

[D.J.T.]

cool thank you so much. i had mine hooked up wrong. gauge is now working properly but my idle is around a grand( don't think that is right) cps adjustment i hope and i have a vac leak somewhere. almost there!! this car sat in a field for over five years before i got it so im just trying to get it back to right. thank you for your help.

DON'T GO FOR CPS. Careful now, high idle can be many different things.. Throttle position sensor, idle speed valve, bad ECU, etc. My car had an EXTREMELY Dirty throttle body & wouldn't shut completely till pressed down so it would idle at 1500. So basically my father took it out cleaned it with brake cleaner & a tooth brush put back in & worked fine after that. Id go with cleaning it 1st since you say the car sat in a field over 5 years & usually my supra idles at 800. so you should definitely fix the vacuum leak & clean the throttle body. If your Supra is working well without any misfires leave the CPS alone. That's for timing NOT idle & im glad i could help!.

 

[D.J.T.]

BTW. Aren't you that same person Selling a Supra On Craigslist, in Tulsa??? The 88 that hit the curb??

 

[JStoked]

BTW. Aren't you that same person Selling a Supra On Craigslist, in Tulsa??? The 88 that hit the curb??

[Ben hacks brothers account]
no, we bought that car. a few pics of it are in this thread on the "other" forum:
http://www.supraforums.com/forum/showthread.php?t=613183
almost have it ready, just have to get some smaller parts that we didn't have spares of.
-ben [/hack]

 

[JStoked]

o ya sry about my gay a.. bro. but yes me and my brother bought it for 750. Has less then 100k on it a 5 speed swap was already done to it.
Should have it road worthy in a couple of more weeks. And the reason i brought up the cps is because when i bought the 7mgte there was not one in it
(there lies the idot i bought it from dumb a soild it) so we put one in it. But it is doing the same thing yours was i can push in on the rod and the idle goes down. so cleaning is a must.