Turbo still doesnt boost.

[GsxEcutioner]

I have an idea! Boost Leak test!!!!!


Boost Leak Test Boost Leak Test... Shoulda been the first thing performed before trying any of the above.

i said i did it already, just never looked at the gauge, i compressed it with air, listened for leaks, fixed all the leaks, still no boost. I have no idea if a ebay cat would mess up flow, but yha.

 

[rush2252]

Okay how does the car run with all of this going on? Does it even pull itself or does it run like a turd? If you suspect its the exhaust choking out try unbolting the downpipe from the o2 housing. It should only be a few bolts to get the job done.


Good Luck
Kolby

 

[GsxEcutioner]

Cat was for looks only aha, uhm it drives fine just no boost -_- .....

 

[rush2252]

im confused.. it drives fine as it runs good etc just the boost gauge is only showing 2-3psi?? Or it is sluggish and takes awhile to get up and go

 

[Boosted98gsx]

You either have something blocking an airway (exhaust or intake) or you have a leak somewhere (exhaust or intake).

 

[GsxEcutioner]

It runs but it's has no top, I can drive it fine city and highway just no turbo......

 

[Boosted98gsx]

Check your cat.

 

[Calan]

i said i did it already, just never looked at the gauge, i compressed it with air, listened for leaks, fixed all the leaks, still no boost.

If you didn't look at a guage, you don't know how much pressure it held, and you don't know how long it took to bleed down. In other words, you STILL haven't done a boost leak test.

Not to sound like a d__k, but your half-assing your way through troubleshooting this problem. You need to slow down, take a deep breath, and systematically think about what is happening and troubleshoot it correctly.

Boosted98gsx said it....either something is blocking airflow into or out of your engine, or it's leaking. So start with a boost leak test...a real one...with a guage and everything... and see if you can hold 20psi, falling to 10psi in no less than 30 seconds...preferably longer.

If that checks out, check for exhaust leaks around the manifold before the turbo. (do a search for "Seafoam").

Here are some more suggestions:

Test your actuator. Disconnect the arm from the turbo and pump about 7-10psi into the actuator nipple, and make sure it extends and retracts freely.

With the arm disconnected, make sure the wastegate moves freely at the turbo and isn't stuck open.

I didn't look at your mods, but check all the lines going to and from your boost controller, and the boost controller itself.

It also wouldn't hurt to do a leak down test to see if you have deeper problems...although I really think you'll find it's something simpler.

Think logically...troubleshoot systematically

Good luck!

 

[bastard dsm]

i say its a bad turbo, undo the vac line to your wastgate and see if it builds boost. if it doesnt then
unbolt the down pipe and if it builds boost then your flex pipe fell apart on the inside or your cat is
trash. if it still doesnt boost then your turbo is bad. we can tell you what to check so many times, if you cant figure it out then pay someone to do it. i have had a car come into my shop with this same problem with a (NEW) 20g and turned out the turbo was bad. guys, if his car drive fine and idles fine then its not a boost leak....come on you sould know this.
if it was so bad that he couldnt build boost the car would run like crap because of the maf. its like having a coupler
pop off, car wont run and if it does it sputters and puffs lots of black smoke.

 

[Calan]

guys, if his car drive fine and idles fine then its not a boost leak....come on you sould know this.

Really? Even if it only leaks at positive manifold pressure?

 

[rush2252]

Just out of curiosity have you been messing with the SAFC? Or tried unhooking it and starting from square one with all of this? Its going to be something simple or another one of those oops i left this out threads


^^^^^^^^^ I was asking this because a few people are having this issue. And logic states that what they are stating is happening shouldnt. If the turbo isnt seized the wastegate works and there are ZERO boost leaks according to the OP then he should be seeing more boost. Im guessing something simple MBC installed incorrectly or hes been messing with the SAFC etc. If the car isnt boosting it shouldnt be running "fine" as he stated

 

[bastard dsm]

Just out of curiosity have you been messing with the SAFC? Or tried unhooking it and starting from square one with all of this? Its going to be something simple or another one of those oops i left this out threads


^^^^^^^^^ I was asking this because a few people are having this issue. And logic states that what they are stating is happening shouldnt. If the turbo isnt seized the wastegate works and there are ZERO boost leaks according to the OP then he should be seeing more boost. Im guessing something simple MBC installed incorrectly or hes been messing with the SAFC etc. If the car isnt boosting it shouldnt be running "fine" as he stated

if you install the mbc incorrectly then it would be like not having a boost controller at all.
so yes it would boost eather way. calan, if you had a big enough boost leak the car would run pig rich when trying to get into boost. all the air the maf just measured isnt make it
to the motor, so what happens? like i said, im sure it might be the turbo.

 

[rush2252]

Same Sound, I changed the turbo, same sound, I did Boost leak test, leaked through the j pipe, so I resealed it, and its fixed, I was leaking through the throttle body elbow gasket, fixed, still the same sound, still no boost 0_o...................

bastard dsm : we suspected this before but the OP states he changed the turbo w no better results. Im thinking there is some misinformation or missing info here..

 

[bastard dsm]

in that case he doesnt have a clue and sould let someone elts fix it.....its like beating a dead horse.

 

[Calan]

if you had a big enough boost leak the car would run pig rich when trying to get into boost. all the air the maf just measured isnt make it
to the motor, so what happens?

Depends what configuration the maf is in and where the leak is. My car has a GM maf in blow through and when I bought it 3 years ago it had a HUGE leak at the IC outlet, pre-maf. The car ran a little rich, but not bogging-down-billowing-black-smoke rich. Back then, I knew very little about this car and I categorized it as "running fine, but very low boost".

We don't know what "the car runs fine" even means. For all we know, it is running pig rich...but without a log or AFR to view, it's hard to tell by a description here in a thread.

The point I was trying to make is he needs to step back and logically troubleshoot his problem, instead of taking the shotgun approach to it.

like i said, im sure it might be the turbo.

It might be...and it might not. It might be that a duck got lodged in his exhaust manifold

@ "I'm sure it might be"

Laughing with ya there bud...not at you...well... not much anyway

 

[rush2252]

...starting from square one with all of this? Its going to be something simple or another one of those oops i left this out threads

in that case he doesnt have a clue and sould let someone elts fix it.....its like beating a dead horse.

Kinda my point with that one.. as calan states I think hes overlooking something simple. This is where its always good to have somebody else there as an extra set of eyes and ears....

 

[GsxEcutioner]

Ok lets start again, I traveled 1 hour and 20 minutes to get the blt done, I borrowed my friends tester, we compressed it, it leaked out of the tb elboe, and the j pipe. I fixed both, still low to zero boost, I switched the turbo with the same results, changed the wastegate actuator , same, unhooked mbc, same, ran straight pressure from j pipe to wastegate, same, then I replaced the turbo gasket twice already, same. I have two mafs, same results. now what? am I still looking it over., btw My logger broke, i have to replace it, and yes i set all SAFC settings back to original settings.

 

[rush2252]

Okay. Logic states if you have a sealed environment from the compressor side to the IM w ZERO boost leaks, the turbine spins freely and you have a + boost source for the WGA you should be seeing boost. If you install a MBC inline from the jpipe to the WGA you should be able to adjust boost. This is assuming the IC piping is free of debris and the car is running properly. Im still at loss to how your driving this car with 0 BOOST or why????

Im leaning towards a faulty boost gauge or something. Why would you drive a car over an hour if you know something is screwed up. Is this a serious problem or one of those 'ive got nothing better to do than make up an issue to pass my time?"

Kidding... but seriously if you've tried everything we've mentioned and your results your stating are truthful then something simple in the equation is at fault. You dont just see "0" boost on a car that passes all of the above tests


On your boost gauge what kind of HG are you seeing at idle?

 

[Calan]

ok...

Although you still didn't say how much pressure it held and how fast it bled during the BLT, I'll move on.

It's unlikely that two turbos would fail with the exact same symptoms, but just in case...no shaft play and the wheel spins freely...right?

Did you change turbo housings also, or just the compressor sides? Did you verify that the wastegate flapper in the housing is not stuck open? (with the arm disconnected, it should just flop around freely).

Your problem is low boost, so running straight pressure from the j-pipe to the WG actuator isn't really gonna help find the problem. That will cause the wastegate to open at fairly low boost. Did you test the MBC off the car? Blow through it at different settings and make sure it works properly. And double-check the way you are hooking it up.

Did you seafoam it and look for exhaust leaks?

Have you done a compression and leak-down test?

You don't happen to have a serious blockage at the intake in front of the turbo somewhere do you?



EDIT:

Damn you type fast Kolby

 

[GsxEcutioner]

Yha turbo spins freely and no shaft play, we changed re compressor side, HG at idle is 19-21 depending on temp outside , yes this is a real problem aha and no I don't think I have a blockage befor the turbo

 

[GsxEcutioner]

never done a comp or leak down test and no seafoam because I am in vegas right now

 

[rush2252]

wait... you stated awhile ago in this thread that you had a major crack in the hotside.. Correct? So you changed the compressor side? Leaving the severely cracked hotside still on the car? A hotside cracked more severly than one I posted a pic of? Im recalling from a PM correct me if im wrong?

If all of the above are correct then you're still running the severly cracked hotside. A crack large enough to effect the flapper from seating. This COULD explain why the turbo isnt building much boost.


Or you could have bent valves and your leaking boost. That is one idea I havent overlooked.

 

[delta448]

Yha turbo spins freely and no shaft play, we changed re compressor side, HG at idle is 19-21 depending on temp outside , yes this is a real problem aha and no I don't think I have a blockage befor the turbo

If you have 20+ inHg of vacuum at normal idle rpm on a 17 year old 7.8:1 CR engine, I think you need to recheck the cam timing. I get about 16-17 inches of mercury at an 850-900rpm idle on my ~84,000 mile 8.5:1 CR engine with good compression.

You really should replace the cracked turbine housing too.

 

[bastard dsm]

well im saying that the turbo could be bad because a freind of mine couldnt figure out
why his car wouldnt make any boost. it had no shaft play and didnt smoke, well i drove it
and it didnt make any boost. took off the intake pipe and had him start the car......wow, it had a bent shaft... wobble wobble WTF. well unless we can help this guy in person its kind of pointless now. as for the maf thing, yea i know about the maf locations, i too am using a
translator and link on my car as well as our shops galant gsx. yea if your running blow threw you wont have anny issues, if pull threw well you get the point. its apperent this guy
isnt doing it right and we are all saying the same thing over and over. i just added another thing that might be wrong,could just be a bashed hot side.......but he wont change it......even after you guys told him time and time again.

 

[GsxEcutioner]

I relooked at the hotside and it wasn't as bad as I made it seem, I get 19-21 at idle with and idle of 750-900, btw what do you mean bent valves? Wouldn't I be able to hear it?