Low Boost
 

I posted this problem on NASIOC with no avail. Whats happening is that I am only getting 9.2psi of boost max. I have a TBE, HKS SSQV and am running the cobb stage 2 91 octane map. I have an aftermarket defi boost gauge that I installed about 2 weeks ago. Both the gauge and the AP read the same psi with a max of 9.2. The car feels fine when I drive it, but this is my first subie so who is to say if it feels fine for what im running.

What I know so far:
The "restrictor pill" is in the hose coming from the turbo.
The BOV is tight and no leaks.
I reset the ECU and the boost didnt change meaning that the ECU isnt removing boost due to knock.

The map that I am currently running is the only map that will work on my car for some reason. I will plug in the white plug and connect the green connects to change my base map. It will flash and then say im done. So then i unplug everything and start the car. When I go to press on the gas it goes quiet as if the gas shut off. If I were to hold the gas pedal down the car would die. I can feather the gas a little and it will climb up in rpm. The strange thing is that when I load the other maps the Tach doesnt move when I push on the gas. I never drove it with any of these other maps, but when I would reinstall the map im running now, everything goes back to normal and it functions perfectly. Perhaps one of you has some input? If not maybe we can meet up and one of you drive it to give me a second opinion or maybe you can hear a leak that I cant. This is my first rex and I cant really hear a difference from what one should sound like.
Help please.

i am decatting the uppipe in the next couple of days so I guess while im taking off the intercooler and such, that sould take care of any hose leaks.

Divorce the AP and/or load a blank map so that you are only running on the stock ECU and see what happens. Also, where *exactly* are you getting your feed to the boost gauge?

I had it installed on the turbo side of the car right behind the t-fitting from the turbo, then someone on nasioc said to install it behind the BOV so I did.

how do I "divorce" the ap?

Boost reads lower after the intercooler than it does directly off the compresor outlet, but not 5 psi. It's actually not all that important where you have it, as long as there are no restrictions in the point you use, and you take into accoutn where it is when you are reading it. It should be consistent no matter where you put it.

"Divorcing" means removing the AP and putting the ECU back to stock, like the AP was never there. It's a PITA though, so actually it woud be a good idea to try some other things before you do that. I am starting to think maybe your boost solenoid is dead.

You have catless TBE, BOV, and absolutely no other mods right?

I'd guess you've got a leak in the intake somewhere... but I can't figure out how *any* of your maps work if that's the case.

Yeah those are my only mods. Wouldnt i have to marry the AP to the car before I can divorce it?

How are you using the AP if it isn't already married to your car?

I think that was a joke...

Okay, not to come off harsh, but if you haven't heard those terms before, you haven't done any research about the AP yet. Go to http://www.cobbforums.com/forums/ and www.cobbtuning.com and read read read. Try calling Cobb first, then post on Cobb forums in the AP subforum, and if you still can't find the issue but have a good understanding of how the AP works (and the EJ20 in general) we will be better able to help you... and more willing, since we don't have to give you a page of background for every one line suggestion on how to troubleshoot issues with modded engines.

If you are loading and running maps, the AP is married to your ECU. You can't use it on another car until it's divorced. It seems that you bought the car with the AP already installed if you didn't already know this. Were there any other mods that were on it before that were taken off, particularly an intake?

It was a joke, I bought the AP and put it on the car.


Before I got the AP the car had the catless TBE, RFL BOV, and the Injen short ram intake. I took the intake off and put the stock airbox back on the car. Then I loaded a map with the AP, then I got the boost gauge. I havnt had time to go back to stock settings yet, and I wouldnt think it would be the map im running. But yes I will revert back to the stock settings and see what that does.

The AP has the ability to read the boost value from the ECU in real time. I would try this first to see whether the boost is actually low or whether the boost gauge is just reading low.

What I was getting to was trying to eliminate or verify the AP/map as the source of the problem. If you have weird issues on a totally stock ECU, then it's mechanical. And if it runs fine, then either your AP is screwy, or you need to get a 100% Cobb originated map and try again.

Also, give a stock bypass valve a try. The RFL may not be leaking under no load, but if the springs are set incorrectly it will leak boost at a specific pressure... like 9.2 psi. The car will also run better in general. Given a choice between the intake and the BOV, I'd recommend the intake instead, because Cobb has maps for it.

first post n00ber. :p

Reading is for chumps!!

You guys are not very good at reading and THEN answering.

I dont have either an intake or an RFL, those were 2 things that WERE on the car.

__________________________________________________ _____________________
If you want to use the correct terms its unmarry instead of divorce. Hence the joke.
__________________________________________________ _____________________

Thanks for the help guys, it would help me more if you fully read my post, so you could fully understand the problem and so we can both save time. ;)

What map are you running anyway?

oh cody not you too...
it says what map im running in my original post.../\/\/\/\

My bad. But pretend I said "blowoff valve" and try it anyway.

Ok I took off the HKS SSQV and put the Bypass valve back on and there is no change in boost. I am in the process of removing the AP right now. Are there any other tips?

Have you done anything with the restrictor pill?And have checked for a exhuast leak?

Hey qksubi. I have checked and the restrictor pill is in the hose. I have not done anything with it. If there was an exhaust leak, such as from the turbo to the DP, would that effect the boost? I think i have seen you drive by a few times. You live over by my friend Dustin who had the evo. Maybe sometime I can swing by and let you check it out.

Wait what car is this? I didn't see that in the first post?

04 rex

Yeah I live down the street! and yes it will effect boost!!! yeah come on by I wont be back until thursday! Are you the guy with the blue WRX? when you changed your exhuast did you get new gaskets? The uppipe to turbo should sealed real well also did you do headers if so thats your problem!

I will be at home today until 3 or so I live at 10558 crystal bay drive past dustins house 2 blocks and turn left Im on the right side of the steet!

Na the blue rex is our other friend cody. I had the silver saturn Ion, which im trying to sell. I bought this 04 silver rex about 3 weeks ago now and its been a hell of a pain. It came with a catless TBE which I had to take off to pass smog. While taking it off I saw that the person who had first installed the TBE had cut off one of the turbo studs to get the stock exhaust off. Then while I was taking the other nuts off, one of the other studs worked its way out. :huh: :eek: :mad: :mad: :mad: :mad: That was the range of emotion I went through when I saw all that. SOOO anyways I fixed it the best I could and put the stud back in and it seems to be sealed pretty good, but by what your saying there has to be a leak. So I am going to take it all apart and I am gonna drill out where the studs were and just use 5 bolts instead of 3 bolts 2 studs. Im thinking that something could be wrong with the turbo as well. Maybe when I take it out I can show you or bring it on thursday to the bullys and everyone can gather around and say "wtf is going on with this turbo".

I think the leak would have to be pre-turbo (re: uppipe, headers) to affect boost like that.

Yeah, a post turbo leak won't drop 7psi. I'm still thinking there might be a boost leak in the intercooler hoses, or even something pre-turbo, but after the MAF.

hmmm. Damn, well I am going to take off the intercooler to get the turbo out and I guess I can check for leaks and then make sure I snug it up when I put it back on. Other then that I really out of ideas. Is it possible that the turbo is just bad? It is making 9psi so I figured that the turbo was fine.

Unless it's leaking oil all over the place, or making awful noises, the turbo is probably fine.

I'm guessing post-turbo intake leak because that would explain the propencity for the car to die at idle, and the boost leak. 9psi sounds a little high for the wastegate control to be out (normally if the solenoid's busted or leaking, you get about 7psi), but that too could be an issue.

If it was an exhaust leak causing you to lose that much boost, you'd easily be able to hear it.

You could always come out to the meet on Thursday and we can poke around under the hood. Make sure you bring a flashlight or two though... it gets dark fucking early! :mad:

Yeah about that...

About 2 weeks ago it was smoking a little from where the turbo is. I was never able to find where the oil was coming from, but at the most random times it would do it. There was a pancake size spot of oil on my driveway one day. There was never a rhyme or reason why it did that, so I bought an oil treatment from Kragen and poured that in. It was a very safe oil additive because I know some can cause more damage then good. Anyways since I used that, the oil burning stopped. There is a brownish mark on top of the turbo. I dont know if it was there before or not but it looks similar to when you burn sugar, its like a blackish hard spot almost looks like tar.... or oil treatment. I dont know, you guys will have to look at it. It might have come from the oil feed line, i hope thats what it is.

Check to make sure the turbo inlet hose is properly attached to the turbo... I know Cody had his come loose at the last autocross and he was burning some blow-by oil that was in the intake track on the turbo itself.

Also, if you've got a blown turbo, I've got a stock WRX turbo or a SBR GT30-10 I'll sell you cheap. ;)

how cheap and how many miles do you have on it?

I'd sell the stock turbo for $100... it's got <40,000 miles on it IIRC...

The GT30-10 has only 2000 miles on it:

http://www.seccs.org/forums/showthre...hlight=gt30-10

Since no one was interested in it, I'd let it go for $500 at this point.

Yah, the hose was on the inlet, but the hose clamp was just completely loose. Easy fix. Hopefully it's somthing simple like that to explain the oil leak, but that wouldn't have anything to do with low boost.

I was looking at getting a new turbo in the future anyways. If the future happens to be now then yes I am interested in at least one of your turbos. How does the SBR GT30-10 compare to the IHI VF30 or the FPGreen in terms of whp and spool?

There was tremendous hope that the GT30-10 was going to be *the* turbo for the 2.0L. Unfortunately, it didn't really live up to the hype. However, I found the lag to be acceptable, and we put down 260awhp on my car, and that was on the stock fuel pump, 'cause the shop that did the work *forgot* to install my Walbro. :roll:

I don't really know how the VF30 and FPGreen work on a 2.0L motor, but I've got to think that the GT30-10 will spool faster than a Green and make about the same power, but will make less torque... at least that's the experience I had on my 2.5L block.

Well if I were to buy the GT30 from you, what other things would I need? Fuel injectors, pump, bigger intercooler? I will most likely just buy your stock one if its in good condition just because im looking at cost now. And I would rather spend $100 on another stock turbo then spend my time trying to fix the studs on mine which is probably broken as is. Im gonna go take a pic of it right now so you can all see where the burnt oil looking part is.

Turbo, injectors (I've got a set of PE800's I can sell ya), fuel pump, intercooler, and a custom tune would be the minimum IMO.

If you need the stocker, just let me know and I can bring it to a meet, or meet up w/ you some other time. Just let me know!

Here are the pics of the turbo. Im pretty sure the black stuff if the oil additive that I added, I figure thats where oil was coming from and that blocked it up.
http://i3.photobucket.com/albums/y62/thumpyJ/turbo2.jpg
http://i3.photobucket.com/albums/y62/thumpyJ/turbo1.jpg
Thoughts...

I would like to get new intercooler hoses for my 04 rex. Does it matter what brand they are? I know there are cheap ones on ebay and then prices vary depending on the brand.

I've heard that Perrin and Samco are both good.

Well I looked and drove his today all I can say maybe the exhuast might be to large for the 2.0 and its not seal properly on the waste gate side but that exhuast is huge :eek:

Oh yeah here is where they moved the maps to!
http://www.cobbforums.com/forums/forumdisplay.php?f=23

Thanks Bro

I don't think that's the problem. I was wrong once in 1984 though.

After I pass my smog check, ill go back to cobb stage 2 and put my dp back and tell you what boost im reaching. (Bellmouth helix v3 dp, Perrin 3in catback).

Ok cool. and tell me the highest boost in each gear so I can see if mine is similar.