helllo
Im looking for some help, and I assume this is the right fourm..

ill make this as breif as I can in discribing it and symptoms.

first off, my car, 1997 Tsi AWD is Stock, No powertrain modifications with the exception of I have the cat converter removed.
when I first got my car, it was reading a shade under 15psi on the my gauge (quality gauge/autometer), I would get the odd spike to 16 or so, but it always hit and held 14-15 psi.
The car worked very good, I was impressed and it pulled good for beeing in stock trim.
over the months, boost starting dropping off. over a few months it went from holding 15psi, down to 12, down to 10 and down to 8, big change in boost numbers. so after doing some tests and looking some things over I figure the turbo must be wore out, and time for replacment.
last boost reading on the old turbo was about 8psi, felt like I was driving a civic, not a talon..

So, this brings us to now, I replace my old turbo with a Brand New T25,
I used a new turbo, New gaskets, new seals, new everything in the swap..
old one came off good, new one went on even better.
So after getting it on and getting the car going and warmed up, I go for a drive, Im going easy making sure everythings ok, taking a good seat and get things flowing again.
2 days later and 600 kms later, I figure break in time is ok and everything should be ok, I finally decide to go to WOT and see how things are.
I was expecting a good pull, much like it did when I first got the car, but to my disapointment, theres nothing, it feels the same as it did when I took the old turbo off.
mind you, it does sound better ( better cleaner spooling noise, haha) but it still doesnt pull half as good as when I first got it and the boost number just arent there.
With a new turbo and other things I know I can check out ( leaks, cracks, etc) I dont know what it can be, I dont know what the problem is, but I know I want it solved.

So...
I am not a mechanic, and Im still fairly new to this dsm/turbo stuff.. I just havent gotton involed in learning alot about it, this is why I ask for help..

Why isnt my car boosting like it used to ?
Ive check for leaks, cracks and other things, I buy and install a brand new turbo and still nothing, and theres no other known problems that I know about.

what can I do, check or change to get my 15psi back, I miss it and want it back

Thanks for you time..
look forward to some replys and suggestions.

Stephen.

What are you using to control your boost? MBC? If so have you checked it out?

When you say you have done checks, Im assuming you did a pressure test of the intake system?

there is no boost controller, she is in stock trim.. however, some people told me to check the "boost control solinoid" ? I have no idea what that is or what it does, im gonna look into tho.

checked for leaks, checked intercooler and piping, and yes, did a pressure test, tested it at 20 psi and it was good.

besides the test, I cant hear any leaks, not sure if you would or not, usually you can ?
either way, everything sounds good and looks good.

im lost...I miss my boost

Boost control solenoid is under your intake. You should see two small rubber hoses going into it.

Maybe you should also check to see that the waste gate actuator is working properly. You didnt mention weather or not you reused the old one, but if its stuck slightly open, you will have a hard time building boost.

You can also bypass the boost control solinoid to see if it is indeed the culprit. Dont unplug it, just run a line from one spot to another as if the solinoid wasnt there bypassing it.

If worse comes to worse, I would check your compression #'s, and also mabey even timing marks.

ok, ill check and try to bypass the boost solinoid, see what happens then.
its a new wasge and such, came on the turbo, i did not use my old one, its all brand new. so i assume its working properly..

something else i heard..
the downpipe ?, its a double walled pipe or something ? and sometimes and inner wall colapses causeing bad exhaust flow and then causeing "bad boost"
anyone ever hear of this ? could something like that cause such a problem ?

Well you are getting the higher boost from having no cat. The proper way to do that is to replace factory fuel pump,get some larger injectors and adjustable fuel pressure reg depending on what pump you get and some kind of tuning like safc or maft and gm maf. Or go fancy with custom chip or dsmlink but you need eprom ecu for that.

As for low boost if the wastegate is closing properly it should be boosting to like 17 or more although again a proper mbc is what you should be using.

I had a problem on my 50 trim it had bad boost and it was the gasket between the turbo to exhuast manifold.I forgot to tighten my bolts between the turbo and exhuast manifold and it blew my copper aftermarket gasket to pieces.
Fixed that and got my boost back!
Boost leaks can also do this but you said you checked and no leaks.I assume you made a tester?
It don't take much to lose boost so it never hurts to check a few times.
Also if you are running the 2g blow off they leak bad I thought at around 12psi.You need to change blow off for a 1g or aftermarket also.That is usually the first mod you do in the 2g.
So here is what to do.Change up fuel pump and get bigger injectors 550 is fine if you are staying t25.Get an afpr depending on what pump you get.
Use a 1g blow off or aftermarket you can get 2g adapters or buy and upper intercooler pipe with correct blow off valve adapter.

You can maybe see if you exhaust is a problem ,you already have no cat but if your muffler is fubared or something that might cause some problems.
My last 50 trim sure hated the restriction from my apexi n1 silencer.I ran and boosted terrible with that thing in there.

Check those exhaust to turbo bolts and that gasket.Ziggy sells a basically indestructible one.

I guess there might be the chance you hurt your engine too since that cat let your boost go pretty high but the 2g blow off should have acted as a safety valve.

The steps to trouble shooting a boost problem is not to install more after market modifications Allan.

Althought you had a couple of ideas in your post, you should not be telling people to go spend another $1000 installing more stuff when it's a simple trouble shooting problem.

Umm Noah he has no cat..this causes boost spiking and runaway boost.
So if he wants to run higher boost than stock he needs the fuel pump,injectors,tuning right?

Also can't see how he can get much higher boost with stock 2g blow off anyway. :rolleyes:

And actually amazed you guys never jumped on him for having no cat. Its not a good idea it caused big time boost spike and creep on my 14b when I put in my apexi n1 downpipe before I did my fuel and tuning mods.

And every upgrade site I have seen for the 2gs has the following in basically this order.
1) upgrade the 2g blow off.
2)Do the boost solenoid restrictor mod for slightly higher than stock boost.
3)upgrade the fuel pump for 15 or so and get a mbc and boost guage
4)to go much higher get injectors and tuning.
And of course optionally get better exhaust and intake happening.

Stock boost is 12 psi, his car was probably running 15psi because of having no cat, and its safe becaus his stock setup can handle it up to 15. He doesnt need a boost controller. You cant DECREASE boost with a boost controller. That complicates things and is more dangerous than not having one. He said his car WASNT spiking past 16 before settling down to 15 again. He wants that same boost back again.

THAT IS WHAT THIS TOPIC IS ABOUT. He has no intrest in upgrading or any thing else but finding out why his car is behaving the way it is now.

SO........WHY would we jump on him when his origional post was CLEAR with what his car was doing before, what it is doing now, and what he has checked so far?

Stephen, I never heard of that down pipe theory but anything is worth checking. Its a good thing your car is stock because it will narrow it down a bit more. The less complications to think about, the better.

Allan, thanks for the help and suggestions, but modding my 2G isnt in my budget nor something i want to do right now
Im not concerned about running high boost, I would just really like my stock numbers back, and right now, im not making the same boost i did as when i first got the car.
However, you said something about that gasket from manifold to turbo, all that is brand new, and i highly doubt its leaking, you would hear something like that wouldnt you ? all that looks good and was all new.


Now, let me get down to thing and answer some questions..
Yes I made a tester, I checked it atleast 5 times and nothing, no leaks could be detected at all, I had 4 guys there helping me and it was dead slient and we couldnt hear a thing.

now, here is where im getting confused and "worried"
Rob, you say stock boost numbers are 12psi ?
When i first got my car, it was hitting and holding 15psi, with the cat still in it, I didnt remove the car untill 6-8 months after i had it.
I cant see my gauge beeing wrong ? it was a quality autometer unit and it was hooked up properly and professionly.
the odd time it would spike to 16, but only for a fraction of a second then drop down to 14-15psi and it would hold that, and it did that in 110% stock trim, with the converter still in the car.

I know my car is stock powertrain wise, I bought it off a older lady, and she deff did not modify any of the car, its outragous to even think that, and she had the car sence new.
sence ive got it off her, ive done NOTHING but remove the cat, other then basic maintence ofcourse. and now, the new turbo.. which i was hoping to get my 15psi back, but i guess not

Each car varies what stock boost is. Everyone will say their stock #'s are this and that. It depends on the actuator spring wich can weaken over time or possibly stiffen, gauges all vary (esspecially autometer) etc....

12psi (ish) is what stock should be "if" the boost control solinoid isnt reducing boost because the ecu is seeing knock.

If you are knocking (phantom or real), removing the boost control solonoid (leave it plugged into harness) by bypassing it will tell you if this is the case or not if your boost returns to normal. Otherwise the exhaust flow, compression, turbo and intake leaks are the most likly causes.

You would hear a bad exhaust leak, and it should sound obvious, but just to be safe, check for severe cracks in the manifold if you have replacd the head to mani gasket and mani to turbo gasket.

Well stock boost is not 15psi.Fact on mine it seems to be more like 10psi.My 97 is bone stock.Owned by female owner.Zero mods.

And I have always read that you can't even get to 15 with the stock 2g plastic leaky blow off.

Do you still have the 2g blow off on your car?

And on my car I had brand new turbo to exhuast gasket but didn't retighten the bolts after installing it and they came lose and blew the gasket out.I had the shield back on so didn't think to recheck them.

And I will also argue that having no cat will make the boost go way high when he figures out why its now way low.My 14b had no mods at first except for the apexi catback and downpipe and it hit way past 15 and had to keep from going full throttle until I got my fuel pump,injectors and maft.

So I would put a cat back in there until you get some support mods for your car.And if you have no boost leaks and no leak at the exhuast gasket possibly our have broken exhuast studs and are leaking at the exhuast man to head another common place on these cars.I guess also you should check your 2g exh man for cracks.Either you aren't getting enough exhuast to spin it up or you are losing it after the turbo.
If the turbo is working properly its got to be one or the other unless the wastegate is not staying closed when it should.
You can also do a quick test by running no line to the wastegate so it can't open at all but very carefully watch your boost guage and don't go full throttle if you are seeing past 15.

But again how is he getting even 15 out of the 2g blow off?
And if his boost solenoid is also still in their and car is otherwise stock won't it pull back the boost when it detect knock and likely he was getting some with it spiking up past 15.He is stock pump and stock injectors.And are you even running premium in there?
With the price of premium a lot of people go lower octane.

I just want to clarify that the stock 2G BOV can hold up to 15 psi, not 12 psi.

Also you should really pay attention to what rob is saying. If you are knocking badly then the solenoid will pull the boost way back. Your second problem is you can't read knock on a stock 2G so you have a bit of a problem on your hands.

If you have an exhaust leak it's not uncommon for it to cause a lot of ticking and the knock sensor will pick it up and the boost gets pull back because of the solenoid being used.

How is the car running generally? Kinda rough at all?

noah, The car works fine, no bad noises, not rough at all.. clean right thought the rpm band.

however, I notice the car is idleing a bit low, the stock rpm gauge is reading about 750, its not to low the car shakes or makes bad noises, i just always thought i seen it closer to the 1000rpm side at idle..

other then that, car works good, just no boost.
I dont know any other info i can give you guys to solve this problem.

im going out to bypass the boost control solinoid in a little while, ill see if that helps.
hopefully....

rob: I can hear nothing even close to a exhaust leak, everything with that is good and quiet. now ticking or whilsting at all, exhaust seems good. I to think i would hear a leak.

allan: yes, Im still running my 2G bov, Ive heard and read alot that they leak.
but i ran my car perfect for months, almost a year at 15psi and it worked perfect, I dont think it was leaking and i dont think its leaking now after doing the leak test numorious times..

like i say before, im lost and i dont know what it could be.

Have you checked your air filter and made sure that nothing was partially blocking the intake in the fender?

My 97 AWD made 15 psi with only the freebie mods.

checked the air filter and surrouding parts, its all good, no damage or leaks or blockage there.

I just bypassed the boost control solinoid and went for a drive..
no change, still the same thing..
no power, no pull.....

Does your exhaust note sound different? Its a long shot but pulling your down pipe off and seeing if there is a blockage might not be such a bad idea.

When you did your pressure test, did you block the inlet of the turbo off, and test the complete system or just the upper half/lower half?

speaking of blockage I know a few people with after market air filters that had a peice that was glued pop off and block the maf. My buddy had it jam right in his turbo inlet once But if you checked it, that puts that idea aside.

Also another long shot but mabey your intercooler is clogged with some oil etc.... Might be worth taking off and rincing out with some varsol or fuel.

This is odd, a stock car should be easy to diagnose a boost failure and intake leak is the culprit 50% of the time and waste gate is the other one. Did you apply compressed air to the actuator nipple to see if it is indeed moving the gate arm on the turbo housing back and forth? I would confirm that is operational as well.

Try those before I start to suggest compression tests and what not to start looking internally into the motor. But we dont want to think of that right now.

Did you bypass the BCS yet? It's probably exhaust leak causing high counts of phantom knock and the ECU is tripping the BCS.
You could even reset the ECU and then go for a run. If it does 15psi then it's the ECU tripping the BCS.

Unplug hose from wastegate.Put a screw in hose.Carefully take car and watch gauge and see if you can get your 15.This will eliminate the car pulling out boost doe to knock.

Just dont' floor it although again doubt you can get much over 15 on stock 2g bv.And it wouldn't hurt to pick up a 1g bv off the board for cheap.
I am not sure if they bolt straight on or need adapter or what.I am going to be running hks ssv on my 2g and have an upper intercooler pipe got cheap off this board with hks flange.

Did you say you bought a brand new t25? I can just imagine what one of those cost from mits?

Or, you could apply air pressure to the actuator to see if its moving correctly.

Or if the BCS is malfucntioning, and the boost you are getting now is because there will be no change from BCS operation to direct WGA feed, you could install a boost controller to see if the boost goes up. If the BCS is stuck, there will be no change between having it in or bypassed. What boost is it making right now anyways???

Or, you can use Allans grenade method with screws and part throttle :rolleyes:

Hey Rob, did you mean for Stephen to connect the pressure line directly to the wastegate actuator without a bleed-off? Since he has apparently done that and is experiencing the same problem, perhaps his BCS is stuck closed, making the wastegate stay open.

Stephen, don't try the grenade method! Try testing the operation of the BCS first. (The problem could even be as simple as corrosion on the electrical contacts.) The test procedure is given in the shop manual. Also, check all the tubes when you check the BCS.

If you had only disconnected the tube from the tee to the BCS, you ought to have gotten a lot of boost. However, this might be like the 'firecracker' method of checking--not as bad as a grenade, but still potentially bad.

As soon as there is vaccume, the line to the actuator wouldnt need a bleed off because vaccume would close the WGA again if thats what you mean in your first comment. MBC's are built with a bleed as well to allow the WGA to close because the ball and spring alone prevent vaccume from reacing the WGA. Is this what you mean by bleed?

And I too thought that maybe he notices no difference between BCS connected and BCS bypassed because of a malfuntion so I suggested to also try a MBC to try raising the boost. But Your idea about using the manual procedure would definatly be a first choice rather than messing around with an MBC.

I wouldn't be too sure of that Allan, this could be a sure fire way for him to solve his problem by blowing up his engine. If he has one of those magical BOV's that can actually hold past 15psi, he may just have a few more problems then what he's asked us to solve for him.

A friend of mine tried something similar and ended up blowing his engine, and he was being careful with the throttle, it boosted to 22 psi on a stock 2g.

Stephen just be very careful with fooling around with said things, turbo cars are a lot easier to blow up then N/A cars, with only a little bit of tinkering.

He has a 2g blow off and you really think he will blow up his motor with that? Its a quick test to just unhook the line to the gate and carefully watch the gauge as you give it gas.You don't floor the car obviously you can easily control boost with your right foot.But just for a little test. If he doesn't get past 8 then its got to be boost leak,bad exhuast gas leak into the turbo from blown turbo to exh gasket or broken studs or bad new turbo.You guys make this stuff sound so complex.
These cars don't blow up like a fuse in an old stove.
I had my 1g to 43 counts knock retard tuning several times and my 1g runs perfect pulls high vacuum.
I ran my car ,the 1g with high boost spiking and creeping when took out the cat with the n1 downpipe ,prior to my fuel and tuning upgrades and never hurt it by carefully monitoring my knock and simply not going to the floor with my gas.You can't make boost without exhuast and if you don't floor the pedal you aren't going to get high boost and we are talking t25 small here.And if he is super worried then throw in a gallon of xylene or toluene into a few gallons of gas.

I know you guys like to be cautious but man you are bordering on paranoia. But whatever, he can try to check his boost solenoid or whatever and try a manual boost controller but unhooking the line is the quickest way to see whats happening.Just as you can hook a line directly from the wastegate to turbo and bypass the solenoid and see what it gives you minimum boost

And no dont floor the car with this test. :rolleyes: But its hardly super dangerous.
And yes my 2g is down and out right now but it was at stock boost with zero mods.And not 100% sure what happened with it but the 7 bolt is likely coming out as just bought another 6 bolt.

If a guy is going to get super paranoid when playing with these cars then just leave them stock,put his cat back in and don't start mucking with the car. He has no fuel support,no pump,no injectors,no tuning,not even sure if he has logger.Amazing you guys aren't preaching to him to get those things first and then worry about how much boost he has.At very least fuel pumps are dirt cheap and easy to install.

Dude, your a tool. Stop trying to help this guy, if he took your advice he'd be worse off than where he is now.

Please, refrain from using the 'submit reply' button!!!

DISCLAIMER: I take no responsibility for any of the results that may occur from Allan's advice.

Wow everyones getting bent out of shape, howbouts we mosey over here

I honestly don't think you want that after seeing the help in this thread.

Stephen, spend some serious time here:

http://members.shaw.ca/costall/1000Q/

Well, yet another thread turned into the "Im Allan, i have a problem thats the same as yours and heres some bad advice I came up with while smoking crack, btw I have a 2g/50 trim/parts to come" thread.

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Unplug hose from wastegate.Put a screw in hose.Carefully take car and watch gauge and see if you can get your 15.This will eliminate the car pulling out boost doe to knock.

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You couldnt think of anything better? Paranoid are we? NO. Not willing to give some one whome MIGHT blow their motor up if they didnt know the concequences? Yes.

Stephen, if you want to be confused and have to read through tedious crap, take Allans advice. Or you can simply put an air source on the actuator nipple and see if its working.


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Well stock boost is not 15psi.Fact on mine it seems to be more like 10psi
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Well no sh*t Shirlock. I said it was 12 ish. Some are 10, some are 11 some are less. Every actuator may behave differently, every boost gauge reads a little or alot different, and every car behaves differently. His USED to run 15 in his stock form and now its not. Whether it WAS actually 15 is yet to be determined.


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And I have always read that you can't even get to 15 with the stock 2g plastic leaky blow off.
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Do you beleive everything you read on tOOners? Have you even tried? We have two people here saying it will, and Stephen said his was holding 15 all day long and held 20 in a pressure test. Drop it already. He doesnt want a 1g BOV cause hes NOT MODDING HIS CAR. DROP THIS SH*T ALREADY.


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And on my car I had brand new turbo to exhuast gasket but didn't retighten the bolts after installing it and they came lose and blew the gasket out.I had the shield back on so didn't think to recheck them.

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Hrmm, thats about the only logical sentence you posted in months worth reading, good point. *claps hands*


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And I will also argue that having no cat will make the boost go way high when he figures out why its now way low.My 14b had no mods at first except for the apexi catback and downpipe and it hit way past 15 and had to keep from going full throttle until I got my fuel pump,injectors and maft.

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Ya, ever hear of boost creep? Thats what happens when you have an AFTERMARKET DOWNPIPE AND EXHAUST which Stephen doesnt have. He said his boost was holding solid. Doesnt sound like creep to me but rather the opposite.


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So I would put a cat back in there until you get some support mods for your car
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Once again another brilliant idea. Where do you see in this thread he WANTS to mod the car? And according to your theory he would be decreasing his boost even more. Good one


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And if his boost solenoid is also still in their and car is otherwise stock won't it pull back the boost when it detect knock and likely he was getting some with it spiking up past 15.He is stock pump and stock injectors.And are you even running premium in there?
With the price of premium a lot of people go lower octane.
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That was almost readable and I was almost gonna say good point again but I think you stole that from what I said above so no points for you.

BTW, your spelling and puntuation still suck. LAP!!

Torrey who the heck are you what makes you such an expert? Never seen a post from you on the board before. :rolleyes:

Whats the big deal? I tell the guy to disconnect
FOR A TEST ,not permanently the wastegate hose and not go full throttle and to watch the boost guage and his logger which everyone on this board is always harping are must have items before running anything past stock boost.

Now if he don't have a logger than around 15 is max he should go.

And I think the proper way to control his boost is not to run no cat which causes basically uncontrollable boost spiking and creeping.

And if he does want to run no cat then he should get a new fuel pump for 100 bucks minimum so he can handle the creeping and spiking that no cat will give him.

These cars are high performance and not the most reliable things. A person better have the bucks to even keep owning one never mind to mod them up.
You guys are starting to sound like broken records.The cars don't blow up that easy.I have owned and played with turbo bikes,supercharged cars and nitroused cars before most of you guys were even born.And I was born in 1958 not 1988.

Turbo cars dont' magically boost themselves to 30psi especially a t too small on a 2g blow off.
You need exhuast flow and that takes putting the pedal to the metal.
There is zero wrong with my advice and testing method.And minimal to no risk.
The car will still retard timing even if the boost solenoid is not controlling the wastegate . The car has safety mechanisms.
You guys need to have a bit of faith in them.

The cars are not made of glass.And if you are going to worry about it then keep them stock.And there is an old saying if you can't afford to pay you can't afford to play.

And my advice is not any different than the standard advice.Put a cat back on or get the suppport mods to run higher boost that you will get without out.Thats pretty radical advice I guess. :rolleyes:

And its the same thing that happened to me.I had my stock 14b.Thru on apexi n1 catback and downpipe with no cat.Didn't have an mbc or any support mods yet.I got creep to like twenty psi.
Fuel cut and all that. I just didn't go full throttle until got the support mods. Problem solved. Never blew it up.Now if couldnt have afforded the support mods would have put the cat back on.

And guys you should remember this is a forum! A forum is a discussion board a place to put out opinions.And Torrey you have the right to call me a tool just as I have the right to ask who the F%%K are you?

Man you guys get serious fast on here.

Check my member number and when I registered. I was modding talons before you were...

Your inaccuracy really disturbs me, and I feel bad for the poor guy that actually takes your advice.

FFS Allan. You don't get boost creep from not having a cat and he has CLEARLY stated that his boost level was solid. Solid, stable, doesn't go past 16 psi... all of that means he is NOT, I repeat NOT getting boost creep. He is in fact getting the complete opposite.

The reason why YOU had boost creep was because of your downpipe and the rest of your exhaust.

Can we PLEASE get back to helping Stephen with his problem. Stop spewing your false information all over the board.

A stock car is not difficult to diagnose if you know what to look for.

Stephen, my apologies that this has come to this point. I know you just wanted some simple ideas on how to fix your problem. Please, before you go and spend a bunch more money on something like a new turbo again or even fuel mods like previously suggested, please go through all the basics.

I think start off with the basics like post above me.


But really I think the whole Allan is a idiot thing is/has gone on for too long. Okay yes I think we can agree he is. He may be 47 years old ( how he got that old with doing something stupid and killing himself is beyond me) But at 47, you'd figure Life/age itself would have schooled him a little bit. But About buying a car that he hasn't seen until the day he drove it home and it fell apart, let alone telling everyone with an IP number on the internet that he has a 2gen POS thats a lot wrong with it.

And Right down to spreading mis information that is or could cause someone to waste moeny or to harm something in his car or the them selfs. Is just F*cking wrong.

STOP IT ALLAN

Now I figured by now, Alan ! your pretty pissed off, or prehaps you have been moved a bit. but I'm not blaming you for this, I'm blaming everyone else on the this UBB (besides Rob) for not telling you to shut the F*ck up sooner ! Its not your fault your 16 year old trapped inside a 47 year old body is it ?


thanks

Don't forget, any hate mail can be forward to my mailbox.

well.....

lets start over...

my car is 100% stock, with the one and only exception of no cat converter.
before and after the converter was takin out I was hitting and holding 14-15psi.
how ? I dont know, most people tell me stock boost on my car should be 12psi... sooo....


so far, Ive tested for leaks, compression and I installed a new turbo, new wastegate and new gaskets for the unit.
I also tried to emiminate the boost control solinoid but I got the same results.

car sounds normal, no signs of an exhuast leak or boost leak.
exhaust sounds normal, turbo spools up good and sounds great.
I only run high test/ premium gas.
I also have brand new plugs and wires in there.
even swapped out the old plugs for new ones to day ( stab in the dark i know )...

Right now im getting roughly 7psi, not good, feels like im driving a geo metro..

Toommorw my plan is to drop the down pipe and try that out..
also i plan to check the timing, providing I can find someone who knows how to do it, in my area that may be a task on its own..

for the record, im running stock T25 turbo (new)
Stock 2G BOV, Stock intercooler and piping.
only thing fancy on my car is some accel plug wires, haha.
Boost was fine for a year after i got the car.
solid 15psi.
I would get the odd spike to 16, but it was only for an instance, and was rare to see..

I think that sums up my car, its problems, its powertrain condition and what ive tested and tried.


Thanks for the help everyone, Id really like to hear some more ideas, I really want to get to the bottom of this.
Im not liking my talon right now, feels like im back in a civic, which is a very scarey thought

Stephen, timing on that car is a problem because it can't be changed without an adjustable CAS:

http://members.shaw.ca/costall/1000Q/answers-minor.htm#adjusttiming1G

noah, with that beeing said, whats the odds of my timing even beeing off ?
is it common for timing to change on a 2g ?

Stephen, test the BCS first. It's a whole lot easier than removing part of the exhaust. If you don't have the shop manual, I can post the explanation, but I'm sure someone on here can post pictures in no time flat.

By the way, the shop manual does indicate that the car can boost all the way up to 15 psi.

greg: I already tried the BCS and theres no change. I "bypassed" it yesterday and went for a little drive, no change at all.

My next step is to drop the down pipe and go for a drive, I cant see there beeing a blockage in my exhaust but its worth a try.
I can just imagine how loud shes gonna be

Stephen, what Greg is trying to say is that if the BCS is stuck, there wont be any change whether its bypassed or not, or at least not much. The BCS bleeds off pressure to create the higher boost when its functional. If its not bleeding and the WGA is seeing that pressure sooner and more of it, it results in lower boost as the WGA opens sooner.

In the owners manual, or in that sensor testing thread stickied somewhere here, you will find the procedure to test it.

My origional thought when you said you werent boosting is that you had almost no boost, but 7-8 psi isn not uncommon if the actuator spring is weaker than most and its what you might run with the BCS removed if that was the case.

Also, your boost numbers before and after seem odd. Do you have a regulator on the compressor you used to do the intake leak test? If so, can you confirm your gauge is calibrated properly? This would also help.

If the compression and timing are both OK, and there are no boost or exhaust leaks, then there are only a few ways to have such low boost:

- BCS stuck closed.
- Bad turbo (or a problem with the internal wastegate).
- Faulty wastegate actuator (soft spring).

Since the turbo is new, the BCS is the most likely culprit.
See solinoid tests here:
http://www.geocities.com/MotorCity/Downs/7678/dsmtests.html
Symptom of a bad BCS is exactly as you indicate, max boost 7-8psi.
I agree 100% with Rob, that if your BCS is faulty and you bypass it, you would see no change in the boost level as you have techincally changed nothing.

Now, why have you in the past boosted 15psi steady, with no aftermarket boost controller?

IF stock boost on a 2G is supposed to be lower than 15psi, then I could only see this happening due to either a faulty wastegate actuator, or simply a leak in the vacuum line leading to the wastegate actuator.

Also, IF 15psi is in fact higher than stock boost and in the future you would like to maintain this boost level, you will need some type of aftermarket boost controller. This is assuming that your higher than normal boost is due to some problem noted above (that will be fixed).

Ok lets keep it civil this time.

He was higher than stock boost as he removed his cat.

He should bypass the bsc and try a manual boost controller or no line to the wastegate for a test and watch boost carefully and control it with throttle. Don't go wide open without careful monitoring.

And Rob no idea why you said you can't decrease boost with a boost controller.That is what they do increase or decrease boost. At least it does in my car. Now if you meant it won't decrease boost when it spiking or creeping then it makes a bit of sense.

And here are few more things that cause low boost:

Shot turbo its new so unlikely.
Wastegate not closing fully. New gate so unlikely.
Wastgate spring week,new wastegate unlikely.

Boost leaks ,says he has tested for them so apparently unlikely.

Leaks in exhaust ,broken exh studs,loose turbo to exh man bolts,blown turbo gasket.

Boost being pulled from bsc due to excessive knock.Possible explanation. Again easy to see by disconnecting line to wastegate or using mbc.

Lets try not to freak today over this no line to wastegate advice.Its given often on the big boards and if done briefly and while watching the boost gauge its very safe.

Very curious to see what the problem here really is. Its pretty much got to be one of the above unless the engine is gone. Compression test can't hurt. Not sure why you guys would check timing or hook vacuum to the wastegate.The vacuum is testing to see if its opening not if its staying closed. His complaint is not enough boost not too much. 2g timing timing is fixed anyway on stock 2g.

And I did have similar problem with brand new 50 trim on my car .It was from not retorquing the exh man to turbo bolts which blew the gasket out. Changed gasket ,tightened bolts spool and boost were both back in spades.

Its one of the above reasons in this post. Willing to bet on it.

They can not decrease the boost pressure below what the actuator will do alone. Unless of course you've got a dual port actuator, and have some check valves and a vacuum reservoir. It works on my 57 trim!

I'll even copy and paste the test right here for future reference:


Solenoids
Applies to 2.0L DOHC Engine (perhaps others...)

Location:
# Boost Control Solenoid (BCS): mounted on the aircan
# Purge Control Solenoid: firewall mount, position #1
# EGR Control Solenoid: firewall position #3 (only on CA cars)
# Fuel Pressure Control Solenoid: firewall position #2

Symptoms:
# BCS: stock vehicle shows 7-8 psi
# PCS: ??
# EGR: Emissions problems
# FPCS: Warm start problems?

Testing Procedure:
Resistance across terminals should be 36-46 ohms (at 68F)

EDIT: Allan, why don't you just copy and paste directly from our posts? It would be much faster.

Because I am not that good with this computer stuff. I am an old guy remember. My first car was a smokey and the bandit ta in 1978 and I was 20 at the time.

Yeah I know the controllers don't lower boost below the minimum actuator level.

I think Noah means to say that your last post is repetition of what has already been mentioned

i read my original posts again, and I forgot to add something.
Over the last few months my car has been ridicuously hard on gas...

I dont know if this would play a factor is solving my problem or not, but I figure i should add it.

im going out to test the BCS in a few minutes, just waiting on a buddy to bring me up an ohm meter so i can check it out

Yup, Rob C's clarification of what I was getting at is right on. He had the idea first, by the way.

OK, paraphrased from the 1997 Talon Service Manual...

As mentioned by others, coil resistance is to be 36 ohms to 44 ohms [at 20ºC.] (The manual says 44 instead of 46 for the 2G.)

The BCS has two ports: an upper and a lower port. It also has an electrical connector at the base.

1. Disconnect and unclip BCS from its mount.
2. Connect pressure hose to lower port and apply pressure, i.e. blow into it. No air should flow out the top port.
3. Connect 12 V source to electrical terminals at base of BCS and apply pressure to lower port. Air should flow.

You should also check the following while you're checking the BCS:
4. Disconnect each hose and confirm that air flows through the hose and fitting.

Let us know how all this goes so we can let you know the next steps.

What numbers did you cyl compression test show?

nathan, I forget the exact numbers right now.
ill test it again tommorw and let you know.

I think the lowest was the high 160's ? 168 maybe ? and highest was 170ish
im not sure, ill get back to you on that one.

I read that the service limit was 130 ?
so even if i wasnt exactly right with those numbers, I would still be well above the limit wouldnt I ? and that wouldnt cause a problem ?

would a bad coil do this ?
I havent tested mine, but it doesnt look the best visually

well its been a few days, and ive spent a good handfull of cash on this, and unfortunatly its still the same.
ive tried everything, replaced alot of stuff, tested alot of stuff and still get no results.
I dont know what the problem is.
its very disapointing.

Have you tested your BCS, as per the instructions on the last page?

Yes Rob I have, tested in 3 times in total just to be sure, seems to be in spec and funcioning properly.
I think its safe to rule the BCS out.

Have you tried a manual boost controller?