0 boost

[HULK]

Ok guys and girls, I have a question. What could I check if my 1990 GSX is not boosting? The car is very sluggish, and you can not hear any signs of turbo spool up, boost, or even an air leak. I barely bought the car, so I am not really familiar with it. The car is stock, for the exception of an open air intake, and a boost controller.
I have searched and found some possible things that can be my problem.

The wastegate: How do I check if its working. I have read that if you you can easily move the spring, then it is shot. Is this correct?

Timing: The seller told me he had sent the car to be a mechanic because it was out of timing. Supposely it was fixed. When I was gonna go test drive it, the car had a hard time accelerating. Even to get to 10 mph. Then a friend moved the sensor on the passener's side of the valve cover, and the car is now a little bit better to drive. You can drive it to 40 or 50 mph, but it wont boost. Not even if you floor it.

Air leaks: Could a leak be the cause for not boosting. My old SAAB turbo, would still spool, even with a major intercooler leak.

14B Turbo: Can it just be the whole turbo unit? How can I check if its the turbo?

Cat: Maybe a clogged cat?

Please help narrow down the problem. I don't even know where to start.

 

[LiquidX]

Start by doing a proper boost leak test.

 

[Bud92gsx]

eFirst check for shaft play in the turbo, in and out, and up and down..Old saab turbo So I'm guessing 12b, something like that?

Also a BOOST LEAK TEST is in odrer here,, as well as cheching the bolts to head and bolts to turbo,make sure thee tight..

The WG and can manually pull the rod and make sure the wg arm is moving..The Wg itself attatch a hose to the niple and suck as hard as you can and see if it will move...

 

[HULK]

eFirst check for shaft play in the turbo, in and out, and up and down..Old saab turbo So I'm guessing 12b, something like that?

Also a BOOST LEAK TEST is in odrer here,, as well as cheching the bolts to head and bolts to turbo,make sure thee tight..

The WG and can manually pull the rod and make sure the wg arm is moving..The Wg itself attatch a hose to the niple and suck as hard as you can and see if it will move...

I had upgraded the turbo on my Saab 9-5 to a Td04HL-15t.
Should I remove the boost controller?

 

[Bud92gsx]

So then your on the stock 13g or 14b in the gsx or the saab 15t? It's kind of confusing..

 

[RadDsm]

Do you have a boost gauge to make sure it's not actually making boost?
If it's not making ANY boost, check to make sure the WGA is hooked up to the flapper.

 

[HULK]

So then your on the stock 13g or 14b in the gsx or the saab 15t? It's kind of confusing..

Oops, sorry for the confusion. No, I used to have a 1999 Saab 9-5 Se with turbo. I was just saying that when I had a major leak on that car, I would still here the turbo spool.
The GSX is a 5 speed, so it comes with the 14b.

Do you have a boost gauge to make sure it's not actually making boost?
If it's not making ANY boost, check to make sure the WGA is hooked up to the flapper.

Yes, the car came with an aftermarket boost gauge. When the car is on, the boost gauge needle is in the vaccum section, and if I punch the throttle, it moves to 0 psi, but doesn't pass that.

 

[Bud92gsx]

Now is the stock gauge reading some kind of boost and the aftermarket one is not perhapps..And your talking in nuetral, not driving conditions, Correct? Or is is not boosting under driving conditions?

 

[HULK]

Now is the stock gauge reading some kind of boost and the aftermarket one is not perhapps..And your talking in nuetral, not driving conditions, Correct? Or is is not boosting under driving conditions?

both gauges show the car is not boosting. Idle, reving, driving, flooring it. Never.

 

[DSM_love_GST]

id say boost leak test, and check to see that the po installed the mbc correctly. Good luck

 

[HULK]

id say boost leak test, and check to see that the po installed the mbc correctly. Good luck

Should I just remove it for now, to eliminate another possibility?

 

[Bud92gsx]

Yep try a boost leak test you might find the root of this evil pretty fast with a boost leak test..

 

[HULK]

Yep try a boost leak test you might find the root of this evil pretty fast with a boost leak test..

Do the ebay ones work? Or can I make a boost leak tester.

 

[Bud92gsx]

Ebay ones work fine, or yes you can make one.. http://www.dsmtuners.com/forums/articles-parts-fabrication/386650-how-build-boost-leak-tester.html

 

[HULK]

Ebay ones work fine, or yes you can make one.. http://www.dsmtuners.com/forums/articles-parts-fabrication/386650-how-build-boost-leak-tester.html

Thanks Bud.

 

[Bud92gsx]

You are welcome sir..Post back with the results please..

 

[HULK]

I sure will

 

[LiquidX]

I use this company for couplers and other sorts of intake accessories. I actually have their boost leak tester as well. I'd recommend getting it as you can easily adapt to any sized turbo simply by changing the coupler.

Intake Leak Pressure Tester

 

[HULK]

I use this company for couplers and other sorts of intake accessories. I actually have their boost leak tester as well. I'd recommend getting it as you can easily adapt to any sized turbo simply by changing the coupler.

Intake Leak Pressure Tester

Thats a nice website. Prices are pretty inexpensicve. Thanks.
I think I'm gonna go ahead and buy one, then going through the hassle of making one.

 

[twicks69]

You can also use www.boostpro.net, or www.frozenboost.com.

Tim Zimmer via Evo Phone

 

[LiquidX]

Tim, the frozen boost one looks to be the same as the siliconeintakes version and they are both prices the same.

I do actually have the boostpro.com tester and while it works and is cheaper, I was having constant issues of the tester popping out of the coupler with enough pressure due to not having a groove on it. I'm sure if you cut it down to leave a lip at the end it would work better but ultimately I prefer the S.I. or F.B. tester.

 

[HULK]

^^Nice information here. Thanks guys.

 

[HULK]

Ok guys, I have some updates.
I havent done the boost leak test, since I haven't ordered the part. But, I did remove the timing cover and checked the timing, and it was ok.
This is how I checked it: I removed the cam gears cover, removed the driver's side tire, valve cover, and spark plugs and wires. I put a straw on the cylinder hole 1 (nearest to the cam gears), and I turned the crank pulley, until the straw was at the highest point. I then checked the two marks on the cam gears, and they were facing each other.
While I was removing the valve cover, I noticed the valve cover bolts were loose and also the bolts on the manifold to turbo. The head looks really clean and in great condition. I just noticed a dmsll scratch on one of the cams.
We also adjusted the sensor at the end of the cam next to the valve cover (don't know what its called), and the car idles fine now. I was reving the car after all of this, and I can hear the blow off valve now, and I saw the psi needle pass the vacuum part.

 

[LiquidX]

When you check the timing, there are at the most 5 marks that need to line up. Cam gears, crank, oil pump, and balance shaft. If you do not have shafts then just the crank and cams get lined up. The CAS needs to be adjusted using a timing light.

The stock ECU expects to see base ignition timing of 5*BTDC. You should have bought your boost leak tester a while ago as you still need to perform a test. I can guarantee you have boost leaks still.

 

[HULK]

When you check the timing, there are at the most 5 marks that need to line up. Cam gears, crank, oil pump, and balance shaft. If you do not have shafts then just the crank and cams get lined up. The CAS needs to be adjusted using a timing light.

The stock ECU expects to see base ignition timing of 5*BTDC. You should have bought your boost leak tester a while ago as you still need to perform a test. I can guarantee you have boost leaks still.

Does anybody know where I can buy a good inexpensive timing light?