Not building boost at all? Possibly the throttle body

[Alexvance]

I went to home depot yesterday and made myself a little boost leak tester, when I got come and stuck it on the car at the turbo inlet I was surprised to find that the only audible leak at 20 psi was coming from the throttle body spring thing at the back.

So I've been looking at the throttle body leak threads, and I'm pretty sure that's my problem and I'm going to replace the seals.

But I want to know, can that cause me to be losing nearly all of my boost? I mean I don't feel the turbo at all when I drive now. Could the throttle body be leaking that badly? I hear a whine that sounds a little like the turbo spool, but at a higher pitch (So I think that's the leak from the TB). Could there be something else wrong?

I'll be investing in a boost gauge very soon (i.e ordering one as we speak), but until then any help at all would be very appreciated.


P.S
This is the gauge / pod combo I'm going to buy:

95-99 Mitsubishi Eclipse Custom Gauge Package

What's the "oil filter adapter" option, and will I need one? (Planning on getting boost, egt and oil press.)

 

[93_tsi_fwd]

Better off looking for a 1g throttle body.

 

[rush2252]

Just some food for thought But if you were technically running no boost then the car shouldnt pull itself over 2k (mine wont on the auto) Yours is 5spd im sure but you get the point. Mine has been blowing off intake piping all week and Ive added some extra clamps to fix it, but if there were no boost then you shouldnt be able to drive. If you not feeling the kick of the turbo on the butt seat dyno its very likely that the stock BOV spring is getting weaker and its leaking even at idle. My T25 installed with the plastic stocker BOV was leaking at idle and only producing about 4psi. What does the stock pos boost gauge read? They arent accurate but is it showing a reading at all?

- Kolby

+1 on the 1g TB I picked up one at pull apart for $20 with all sensor included

 

[Alexvance]

Just some food for thought But if you were technically running no boost then the car shouldnt pull itself over 2k (mine wont on the auto) Yours is 5spd im sure but you get the point. Mine has been blowing off intake piping all week and Ive added some extra clamps to fix it, but if there were no boost then you shouldnt be able to drive. If you not feeling the kick of the turbo on the butt seat dyno its very likely that the stock BOV spring is getting weaker and its leaking even at idle. My T25 installed with the plastic stocker BOV was leaking at idle and only producing about 4psi. What does the stock pos boost gauge read? They arent accurate but is it showing a reading at all?

- Kolby

+1 on the 1g TB I picked up one at pull apart for $20 with all sensor included

I know what you mean about the 2k thing, that happened to me when my bov came off, my car can't vent for poop.

I'll have to keep an eye out for a TB, I never see any 1gs at the pick and pull though =/

Stock boost gauge reads off some calculation of rpm and your throttle position etc, It still things I'm doing great. I think I'll save my money on the mechanic re-visit I was planning on earlier, and see what some new upper intercooler piping + a new bov will do for me.


Say I were to find a 1g TB, would I just plug it straight onto my engine? And is the 1g TB better than the 2g or something?

 

[rush2252]

I know what you mean about the 2k thing, that happened to me when my bov came off, my car can't vent for poop.

I'll have to keep an eye out for a TB, I never see any 1gs at the pick and pull though =/

Stock boost gauge reads off some calculation of rpm and your throttle position etc, It still things I'm doing great. I think I'll save my money on the mechanic re-visit I was planning on earlier, and see what some new upper intercooler piping + a new bov will do for me.


Say I were to find a 1g TB, would I just plug it straight onto my engine? And is the 1g TB better than the 2g or something?

They are a BBTB (big bore Throttle body) I found mine off a 1g NT car. The one that looks like the 4g63 but NA. And yeh they are larger bore. They are a direct replacement. The three vaccum lines that plug in on top face the opposite direction but thats an easy fix just run some longer line. I belive they are like a 3in/60mm bore as opposed to the 2 1/2in/50ishmm bore. Dont hold me to the exacts but they are larger. The only major difference in modifying one to fit is the stock 2g has a formed elbow that bolts to it and the 1g has a 3in nipple. I just cut the elbow off the 2g so I had a 45 and used it with an adaptor to make it work with the larger 1g.


-Kolby

 

[93_tsi_fwd]

Look for a 1g turbo TB. its a direct bolt on and is 60mm. Not the N/A 4g63, That, you'll need a new TB elbow to make it work.

Stock 2g tb's are 52mm.

 

[Alexvance]

Okay so a 1g turbo TB will fit with the upper piping I'm getting from Dejon without any modification then? I'm also a little apprehensive because what if that one leaks too then I'm back at square one again.

 

[4pistons]

It would take a HUGE leak to not have any pressure in the intake at all. When you do your leak testing what pressure do you test at?? If you see pressure in your piping then obviously the leaks aren't enough to leak all the boost from your turbo. Your turbo moves way more air than the nozzle of your air compressor does!

It sounds more like your wastegate is always open. Remove the actuator arm and move the wastegate lever back and forth. Does it move freely through its full travel? Does it close completely? If you re-attach the actuator arm does it hold the wastegate open?

Are you relying on the stock boost gauge to measure pressure? It doesn't do that. It 'calculates' boost from airflow, temp, outside pressure, rpm, etc. Maybe it doesn't work anymore. Until you get a real boost gauge on it you'll just be guessing.

Rick - '91 GSX

 

[Alexvance]

It would take a HUGE leak to not have any pressure in the intake at all. When you do your leak testing what pressure do you test at?? If you see pressure in your piping then obviously the leaks aren't enough to leak all the boost from your turbo. Your turbo moves way more air than the nozzle of your air compressor does!

It sounds more like your wastegate is always open. Remove the actuator arm and move the wastegate lever back and forth. Does it move freely through its full travel? Does it close completely? If you re-attach the actuator arm does it hold the wastegate open?

Are you relying on the stock boost gauge to measure pressure? It doesn't do that. It 'calculates' boost from airflow, temp, outside pressure, rpm, etc. Maybe it doesn't work anymore. Until you get a real boost gauge on it you'll just be guessing.

Rick - '91 GSX

How do I remove that arm? I looked at it and tried to move it by hand, but I couldn't budge it. I was worried it was stuck open too, but I don't know how to check that myself. I searched but all I got was you need to remove a pin or something, and when I looked it was far too cramped down there to get at anything.

I don't even bother looking at the stock boost gauge, I know it means nothing.

 

[93_tsi_fwd]

There is a cotter pin thats holding the WG arm to the nipple of the WG flapper. try removing the AC fan so you;ll get more room. (3 10mm bolts)

or

Another way to check it is get pull off the vacuum hose and use a compressor to blow on that WG hose. If it moves or not.


PS: If you need help, let me know.

 

[4pistons]

I looked at it and tried to move it by hand, but I couldn't budge it.

It's very hard to push open by hand. There's a spring in the canister that holds the wastegate shut until about 8 psi. You have to take the arm off to move the wastegate flapper by hand.

 

[Alexvance]

There is a cotter pin thats holding the WG arm to the nipple of the WG flapper. try removing the AC fan so you;ll get more room. (3 10mm bolts)

or

Another way to check it is get pull off the vacuum hose and use a compressor to blow on that WG hose. If it moves or not.


PS: If you need help, let me know.

Hmm, might have to take you up on that


And are you sure the fan has 3 bolts? I took off the top 2, and the one on the bottom left (towards the inside of the car) and couldn't get it off. I gave up because I had to go and had oil all over my arm

I guess I'll have to figure out a way to get my compressor hooked into that hose to see if it moves at all.

And an update: I tightened my stock bov and upper pipes up and I'm getting faint boost, enough to make my BOV sound at least, but it still feels very much like I'm not getting what I should be.

Cant wait for the gauges to get here that'll clear so much up.

 

[Alexvance]

Update:


So apparently it is all in the TB. The mechanic called and said that the majority of the smoke was coming from there. I said "Surely I'm not losing that much boost from just the TB" and he said "yep, there's a lot of smoke coming outta it".

Guess I'm going to replace those seals myself. Ughh, I'm scared to take something so important apart myself ><

But still happy it's not a hole in the intercooler or something!

 

[habitatguy187]

Update:


So apparently it is all in the TB. The mechanic called and said that the majority of the smoke was coming from there. I said "Surely I'm not losing that much boost from just the TB" and he said "yep, there's a lot of smoke coming outta it".

Guess I'm going to replace those seals myself. Ughh, I'm scared to take something so important apart myself ><

But still happy it's not a hole in the intercooler or something!

I find that a little hard to believe, but I guess it's possible. And good luck with the shaft seals, you'll do fine. It's really not that hard at all. Just take your time you'll see how it all works, it's pretty simple actually. And once you figure out how it works, you'll be able to put it back together no problem.

 

[4pistons]

How do you get smoke out of the throttle body?

 

[rush2252]

How do you get smoke out of the throttle body?

Read the ENTIRE post.. he had it smoke tested because they couldnt find the leaks with a boost leak tester

 

[Alexvance]

I find that a little hard to believe, but I guess it's possible. And good luck with the shaft seals, you'll do fine. It's really not that hard at all. Just take your time you'll see how it all works, it's pretty simple actually. And once you figure out how it works, you'll be able to put it back together no problem.

That's what I thought. Thanks, I'm sure I'll figure it out. You're right, once you see how things are working it does become a lot clearer.


For anyone with a similar problem reading this thread:

- Do the DIY boost leak test.
- FIX WHATEVER IS LEAKING
- If it's still not fixed, then go to a mechanic, I could have saved about $250 + time + being late to work and collage if I had done that first.

Apparently you can indeed loose a lot of boost through something like a TB.

If you have this exact problem you can get the parts here:
Throttle Body Seals
BISS O-Ring
BISS Screw
Thanks to snowborder714 for the links.


Oh and the mechanic wants $170 to fix it (I don't know if that includes labor hours or not) so err... you're kidding right? I said to the guy "you know the seals and a new BISS screw cost about $20 total online... maybe less."

Do it yourself.

 

[habitatguy187]

If you follow that link on the TB shaft seals from Talon, Laser, Eclipse 1G Info DSM you can pick up the shaft seals for about $0.75 from the hardware store instead of $12 from machv. The shaft seals are the same for 91-99 models so you're good to follow that link on what seals to pick up.

 

[djluda00769]

So it was the TB? I just instaled a Big 16G this last weekend and everything was going great! but coming home to night, I launch from a stop light and I noticed i wasn't making any boost and there was a high pitch spooling sound? No leaks, smooth idle, only when i rev up i get that high pitch sound and NO Boost. I read the post but just wanted to ask

p.s.- I have HKS BOV, AM Boost Gauge, Stock Upper IC hose. Please help

 

[rush2252]

Ah another Okie on the site welcome. Dont hijack the thread though. If your getting a high pitched whining and no squeal check for shaft play. FYI start your own thread or make sure the OP has his issue solved before asking for more help


Kolby

 

[4pistons]

Guys, there's NO WAY your throttle body leaks enough so you have zero boost! A B16G turbo can flow 550 cubic feet/minute of air. A TB leak past the seals cannot. You have issues in other places.

Did you actually do a leak test? Is the turbo spinning freely? Is your wastegate operating properly? Is your boost gauge hooked up and operating properly?

Rick - '91 GSX

 

[rush2252]

Guys, there's NO WAY your throttle body leaks enough so you have zero boost! A B16G turbo can flow 550 cubic feet/minute of air. A TB leak past the seals cannot. You have issues in other places.

Did you actually do a leak test? Is the turbo spinning freely? Is your wastegate operating properly? Is your boost gauge hooked up and operating properly?

Rick - '91 GSX

Did you read his entire post? Hes checked all of the above. Hes more or less stating the car isnt boosting well and he isnt feeling the turbo at all. Hes had it boost leak tested and even smoke tested at a local garage. The TB seals are they ONLY leak in the system. Nobody has mentioned a possible leak down and timing check as of late.

Kolby

 

[Alexvance]

Did you read his entire post? Hes checked all of the above. Hes more or less stating the car isnt boosting well and he isnt feeling the turbo at all. Hes had it boost leak tested and even smoke tested at a local garage. The TB seals are they ONLY leak in the system. Nobody has mentioned a possible leak down and timing check as of late.

Kolby

Bingo.

When I installed my gauge I found I was making about 3 lbs of boost, and hitting around 15 (i think) vacuume.

I am, as I type, removing the TB to change the seals. I wanted to get it done before I put my 16g in


Oh and if anyone knows how the hell you remove that coolant (Possibly return) line on the very bottom under the TB it'd be greatly appreciated. Just taking a break right now because I was getting too frustrated >< didn't want to break any tools haha.

 

[4pistons]

Did you read his entire post?

Yes I did. I was responding to djluda00769 question on 5/06/09. I was throwing out all the things he should check before he assumes it's the TB seals.

Yes, it was sort of a sidetrack to this thread. Sorry.

Rick - '91 GSX

 

[andiamo23]

what ever happened to this? what was the solution to the problem?

 

[Alexvance]

Yes there was, and it's kinda silly looking back. My turbo was going. About a week after all this (and replacing the TB seals + biss screw) my exhaust started spewing out a white / blueish grey smoke, i took off the intake and the turbo was blown. Had 170,xxx on it.

Have a 16g in there now and can build solid boost all the way up to 23ish with a pretty leak-free system. (not that I want to go that high, but accidents happen -_-)

in short my turbo was on it's last legs, and i think that's why my boost was so poor

Sorry for the thread revival, just found a PM reminding me I didn't clear this one up.