Boost is read, but the car is SO slow!

[Absolutegtr]

Hello. I have been a member for some time, but I tend to just search and not post. Anyways I have come across a problem that I cannot find an answer on any type of forum.

Anyway, the problem car today is a 1992 Eagle Talon TSI AWD. Here is the problem:

This car is SO incredibily slow. When driving in first gear and I give it full throttle, my boost gauge reads 9-10 psi with a second or two...but my rpms rise very slowly. I have already done a boost leak test, and for some reason I always have air leaking out of the breather, and if I close that, it will just come out of the oil dipstick. I have already changed my PCV valve to one that works great (previous one was completely shot) and no still difference. Here are my compression results (Car was at normal operating temp. and I had the pedal to the floor...i followed the instructions on vfaq) The results from left to right:

160, 155, 150, 170...i feel that the results are exceptional, car has 190K miles on it, but engine (6-bolt) has only 10K on it...had a complete OEM rebuild.

Well here is my theory...The boost gauge is hooked up after the throttle body, so I assume there are no boost leaks prior to the throttle body, because the boost gauge would not read 9-10 psi. Right? (Previous owner said that the throttle body shaft seals are shot...still have to replace)

So what do yo guys think? Where could I be leaking from?

PS: The turbo has extremely little to zero shaft play and the turbine spins freely.

 

[Nate_dogg]

if you have a A/F gauge, and the means to change fuel mixture, make sure you are not to lean. If the leak you hear sounds like a small leak I would not think that is the main problem, but if the leak sounds really open and free moving then you should fix that first.

 

[Absolutegtr]

You see thats the thing, I do not hear any leaks when I perform a boost leak test. I dont know if i am doing it right (I dont see how I am not) ....but whenever I do the test, all I ever get is air getting into the crankcase, and all it does it come out of the breather or the oil dipstick If I close the breather and open up the dipstick.

Any help would be much appreciated.

Just for put it out there if this helps any....My vacuum is at 21-23 and my max boost is at around 9.

 

[Nate_dogg]

Im sure there is a link on this site explaining how to do this check, but if all you are doing is pulling off your turbo intake pipe and capping off the turbo, then pulling off your BOV vac line and inserting your air compresser nozzle into that, then that is correct... well i hope that is correct that is what i have been doing.

But what is your fuel mixture reading under boost???

 

[chuckg]

When I do a boost leak test, i take off my intake and put a special thing my buddy made onto my turbo and pump it up, leaving the bov alone. My .02

 

[Absolutegtr]

Well when i perform the test this is what I do:

take of the whole intake. Clamp on the boost leak tester thing on to the turbo, and hold my air compressor nozzle to the valve stem and try to get to 20 psi, but never reaches there...gets to like 10psi and loses air fast. AND THATS IT. Am I missing a step? When I do this the air just travels to the breather and comes through that.

HELP!

 

[Nate_dogg]

what breather do you speak of?

 

[GVR4592]

I know you said that the pcv valve is ok, but can you blow through it?

 

[Nate_dogg]

Oh im sorry you are talking about your valve cover breather, I forgot how the pcv valve was set up, i just have mine hooked to a hose that runs down beside the tranny and i plugged the line that went to it from the intake.

 

[Absolutegtr]

Oh im sorry you are talking about your valve cover breather, I forgot how the pcv valve was set up, i just have mine hooked to a hose that runs down beside the tranny and i plugged the line that went to it from the intake.

Well I have my BREATHER just in hose form with a small air filter attached on the end to catch any oil. I too plugged the port back into the intake.

I know you said that the pcv valve is ok, but can you blow through it?

Only in one direction...and that is the direction that leads back into the intake manifold. If I blow into it in the other direction, it does not work, no air will get through...and this is how it is supposed to work; correct me if I am wrong.

 

[rabenne]

check the pcv... I thought valve stem seals... replaced pcv... no smoke

 

[toojung2die]

Well when i perform the test this is what I do:
take of the whole intake. Clamp on the boost leak tester thing on to the turbo, and hold my air compressor nozzle to the valve stem and try to get to 20 psi, but never reaches there...gets to like 10psi and loses air fast. AND THATS IT. Am I missing a step? When I do this the air just travels to the breather and comes through that.
HELP!

The air pressure is leaking past the turbo oil seals, down the oil return tube, into the crankcase and coming out the breather. Both my original T25 and current Big T28 do this. It's normal. If you take off the oil filler cap you can hear the air bubbling up in the oil pan. Disconnect the lower IC pipe from the turbo outlet and connect the boost leak tester to the lower IC pipe, eliminating the turbo and do the boost leak test again.

 

[Absolutegtr]

The air pressure is leaking past the turbo oil seals, down the oil return tube, into the crankcase and coming out the breather. Both my original T25 and current Big T28 do this. It's normal. If you take off the oil filler cap you can hear the air bubbling up in the oil pan. Disconnect the lower IC pipe from the turbo outlet and connect the boost leak tester to the lower IC pipe, eliminating the turbo and do the boost leak test again.

Okay, I still need to do that...but lets say that if I do that and there are no boost leaks whatsoever....does that mean i have to get another turbo or what? If you say it is normal, than how else would air get into the crankcase?

 

[toojung2die]

One step at a time. Do the boost leak test without the turbo in the equation. Fix the other leaks you find. The PCV valve was mentioned. They're notorious for leaking, even brand new from the dealer. That'll leak pressure into the valve cover.

I had a really bad boost leak develop recently. The car ran fine as long as I drove like an old lady. The car would bog and buck and blow black smoke whenever I tried to get into boost. I would read 9-10 psi on the boost gauge even though a lot of pressure was being lost. A boost leak test found the problem quickly. I fixed the leak and it runs strong again.

 

[Absolutegtr]

One step at a time. Do the boost leak test without the turbo in the equation. Fix the other leaks you find. The PCV valve was mentioned. They're notorious for leaking, even brand new from the dealer. That'll leak pressure into the valve cover.

I had a really bad boost leak develop recently. The car ran fine as long as I drove like an old lady. The car would bog and buck and blow black smoke whenever I tried to get into boost. I would read 9-10 psi on the boost gauge even though a lot of pressure was being lost. A boost leak test found the problem quickly. I fixed the leak and it runs strong again.

Alright will do...I bought a PCV valve from the local automotive store, so it is not OEM. Anyways I shall keep ya'll updated

 

[Deadly BlaZe]

Is your car blowing out black smoke from the muffler under boost?

 

[NewTurboTuner]

Yeah... does it smoke when it has problems?

 

[Absolutegtr]

That is the thing there is absolutly no smoke at all....no smoke while idleing or WOT!

Anyways, I tested at the LICP...the thing is I gerryrigged something together to make the boost leak tester fit on and it worked. I did have a very small amount of air leaking out of the boost leak tester due to the gerryrigging ;-) So I could not find anyleaks at all and no air was entering the crankcase as well....So it seems as though the air is entering the crankcase via the turbo oil return line...

What now? I hope this is a cheap fix, , knock on wood.

 

[Absolutegtr]

Alright, well I just tested at the throttle body and everything..there seems to be no leaks (I think there is in one at the throttle body shaft seals) but I can not hear any.

But like I said, and I have found out that when attached to the turbo [boost leak tester] the air is going through the oil return line and the oil is bubblng :-( ....Also I performed this test when the engine was cold...it was sitting in the garage for like one day.

Anyways, any info or help to help solve this problem would b much appreciated!

THANKS

Sami

 

[Absolutegtr]

bump?

 

[blackrosenova40]

Did you ever fgure out your problem cause I have the exact same problems you do and its ticking me off.