1G NO boost

[zanderson]

I just recently got my 1990 Talon TSi AWD on the road for the first time and I can't get into boost. It runs strong all the way to redline but my boost gauge just sits at 0. The car doens't pull, so its not a bad gauge. I have read many threads on people with boost problems such as not being able to get above a certain psi or their turbo falling on its face, and have taken quite a bit from that. I checked the way my blow off valve is hooked up and made sure my waste gate is cloesed(pulled the turbo) also the turbo has no shaft play. To my knowlege everything is hooked up correctly, but somewhere along the line I have a problem or have overlooked something. I have an ebay 16g, not my choice, but it came with the car. I also do not have a MBC. Any sugestions would be very much appritiated.

Thanks,

Zach

 

[Bud92gsx]

Have you tried a boost leak test..Does the wastegate arm move when you pull on it..

 

[SBstar]

Check that the wastegate arm is connected. If it is, pull the intake and check that the turbo spins freely. I'll put money on one of the two.

 

[zanderson]

I have already checked the waste gate, I didn't try and pull the arm, but it not opening would cause an over boost situation. Haven't done a boost leak test yet, need to find time to get an aircomprsor. I would think that a boost leak big enought to keep me completly out of boost and sit at 0 vacume would make the car run like ass, but it runs strong all the way to readline.

 

[crash89]

Do you have a wideband, or anyway to have a look at your Air/Fuel? Im betting on a pretty big boost leak. And if thats the case your running lean as hell! Im having a kind of similar issue with my spyder, I can only manage about 8lbs of pressure from the throttle body elbow through the throttle body.. Its making my a/f ratios crazy lean at idle...

 

[SBstar]

If the wastegate arm was disconnected, the actual wastegate passage would be open constantly, causing 0 boost. There shouldn't be a boost leak on the planet big enough to cause you to not see any boost. But if you're relying on the stock gauge there actually may be some boost being produced that it isn't showing. Again check the turbo, pull off the intake pipe and check for shaft play and ensure it spins freely.

 

[GRAVEDIGGER]

If the wastegate arm was disconnected, the actual wastegate passage would be open constantly, causing 0 boost. There shouldn't be a boost leak on the planet big enough to cause you to not see any boost. But if you're relying on the stock gauge there actually may be some boost being produced that it isn't showing. Again check the turbo, pull off the intake pipe and check for shaft play and ensure it spins freely.

Perfectly said Shane. Check to make sure that the wastegate flapper door isn't getting stuck open. Also check to make sure that there isn't any significant shaft play and make sure the turbo spins freely. This should take 10 minutes or less to check.

 

[zanderson]

Perfectly said Shane. Check to make sure that the wastegate flapper door isn't getting stuck open. Also check to make sure that there isn't any significant shaft play and make sure the turbo spins freely. This should take 10 minutes or less to check.

I have previously stated twice that the waste gate has been checked, and adjusted all the way closed. I had the turbo pulled to fix my oil leak at the oil return to the pan, after double checking the waste gate again once the turbo was pulled I decided it was time to ask for advice. I no longer have any idea where to go from here and can't find anything more than boost leak test, WG actuator arm coming off, or waste gate stuck open or mis-adjusted. The turbo has NO shaft play and spins with perfection. The turbo wasn't on the car when I got it, and it appeared to be new. The only bad thing I can see is that its an eBay 16g, but many people are running them and most have been fine. Also I forgot to state it before, I have an aftermarket boost/vacuum gauge. I have 16psi of vacuum at idle. When driving the car runs pretty well, doesn't bog or cut out. I ran gears 1 - 3 all the way to redline to see if I would build boost in any gear and I didn't. I also have a wallbro 255 fuel pump and an AEM FPR. I plan on getting a boost leak test done this weekend, I know that a few exist, but a boost leak keeping me completely out of boost and not make the car run like ass?

 

[razrman8]

I've had this problem before. One would think you'd have a studder of sorts with a leak.

Anyway, what happened with my situation, after a week of diagnosis of my GSX, I'm talking fuel check, boost leaks, air filters and more. I finally figured out what it was. My culprit was clogged cat in the exhaust. Only let me build 2 psi on a Evo316.

Unbolt your down pipe from your o2 housing and see what you get. It'll be loud, but you'll know if it is or isn't a problem

Though a boost leak should be performed.

 

[SBstar]

Ok, now that you've done/stated you've done the first two things suggested we can move on to other issues. We can't assume you know that your turbo spins freely and if the wastegate arm is hooked up.

razrman8 is correct, a clogged exhaust, usually the catalytic converter can cause boost issues in that the exhaust cannot flow freely causing excessive backpressure. It'd be a good idea to check that. Also in the exhaust category a large pre-turbine exhaust leak will also wreak havoc on boost issues, however much like a boost leak, you would most likely notice driveability (bucking) issues.

Also when you removed the turbo you ensured the wastegate flapper closes fully and there are no cracks? A large crack around the wastegate, or a flapper that does not fully cover the wastegate passage will cause exhaust gasses to bypass the turbine wheel.

Also please fill out your vehicle profile so we can understand your current setup.

On a lighter note. I think I figured it out! This flintstone engine you've installed here does not have the pressure needed to spool a turbo of this size...Gas mileage however should be excellent!

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[zanderson]

I've had this problem before. One would think you'd have a studder of sorts with a leak.

Anyway, what happened with my situation, after a week of diagnosis of my GSX, I'm talking fuel check, boost leaks, air filters and more. I finally figured out what it was. My culprit was clogged cat in the exhaust. Only let me build 2 psi on a Evo316.

Unbolt your down pipe from your o2 housing and see what you get. It'll be loud, but you'll know if it is or isn't a problem

Though a boost leak should be performed.

I might as well have it cut off at the header . I don't have a cat the guy before me welded up this rediculous exhaust, starts at a 3'' down pipe and prgressivly get bigger to about 5.5". I'm pretty sure I have a picture on my profile if you want a good laugh. The guy who originally owned the car had a sence of what he was doing with the tubo and the old school hks fuel management setup, but then he left it to his brother who gutted the full interior: headliner, door pannels, back seat and carpet. Said he was going to make it into a "RACE CAR" . He had a long way to go before worrying about the minor weight reduction. I picked it up with the motor completly ripped apart and it had been sitting in the trees for a few years.

 

[SBstar]

Alright, now would be a good time to state your full mods and tuning. Maybe we can get a view into whats going on.

 

[zanderson]

Alright, now would be a good time to state your full mods and tuning. Maybe we can get a view into whats going on.

Car is stock for the most part, when I put the motor back together everything looked factory to me, the car had a walbro 255 fuel pump, the 14b that came with the car was toast so I put on the 16g. I also have a AEM FPR. Pretty sure it sits at 40psi at idle. Can't forget about jet exhaust!

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Would not having enough back presure cause problems? I would think it may not run great, but shouldn't cause boost problems....?

 

[SBstar]

There is no backpressure needed for at turbo. In fact I ran open O2 for quite a while haha!

Do the boost leak test and check back in with those results. I'm assuming that when you installed the exhaust it didn't have any noticeable restrictions, rags stuffed inside, etc. Might as well check that the exhaust is flowing freely out the exit in the rear. Why don't you snap a pic of your engine bay and share that as well, especially down near the turbo. I'm assuming you have stock intercooler piping and sidemount intercooler? Perhaps something is clogged it that route?

 

[zanderson]

Yea, stock. Didn't think about a clogged intercooler. Exhaust isn't clogged I could forsure get my head in it and take a look around again for shits and giggles . It is definatly clear and it was flowing out the back steadily, theres no dought in my mind, thats not the problem.

 

[xxsupralvrxx]

Now heres another question have you checked your vacume line to your boost gauge for a rip, tear, or hole? just a stupid idea.. Another is since it is a egay turbo possibly just a super weak wastegate? I know on my old 14b I had to swap a new accuator just to get the car run factory boost when I had first bought her. The old one was so weak, would it blow open around 4-5 psi

 

[zanderson]

A bad WG actuator could definately be a posiblility, If I don't get somewhere with the advice people have to give here soon I'm going to try and find another WG acutuator to try. I no its has nothing to do with the guage I would have to be extreamly niave to not feel the car get into boost. Especially with a 16g.

Here are a few engine bay pictures of the turbo in the car. There not great, so feel free to ask for more. Once I get the turbo back in the car here probably tonight for I have nothing elso to do and getting this car on the road is becoming more and more of a priority due to sky rocketing gas prices and the crapping wheather discouraging me from wanting to ride my bike. I have a nice camera and shouldn't have a problem getting a good picture of just about anything in perticuar that might be wanted.

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Also, for those of you that might be interested this is how the guy that I bought the car from had left if sitting in the trees(Minus the prothane motor mounts), but he had been working on gutting it so it could be his "RACE CAR". He might have actually had a race car had he spent less time gutting it and invested more time into putting it back together.

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[Tyeler18]

I figure ill chime in. I've spent the winter helping with this build. Although I haven't touched it much since it got running, I do know that there's no exaust leaks and the turbo is fine. Wastegate and boost leaks are what I believe the problems are. Hopefully will get some testi g done this week.

 

[zanderson]

This car started out just needing timming done when I picked it up. We must have set the timming a couple teeth off and therefore when the compression test came back 50 - 10 - 30 - 25 we assumed the guy lied about putting a new head on it. Figured I was seeing the results of bent valves. The valves had a decient amount of cabon build up on them, but other than that everything checked out. This car has sat in the garage way to long. Tyeler18 and I have put well over a 100 hours into getting this thing up and running. Those long hours seemed to pay off with the car sitting in the garage. Everything seem great got it running, then idling good, then went through a run around with the shifting after replacing the clutch, should have replaced the shift fork and pivit ball while in square ONE. It is way easier to pull the trany off and get it back on with the motor out of the car! Lesson learned! We have now got the car driving and running strong through all gears.

****This was all prior to posting this thread****​

I still have no idea what would cause a NO BOOST situation, it runs without cutting out or bucking or anything out of the ordinary for that matter, I pushed it all the way to redline and still no noticable problems. I will be replacing shift cables this weeked, must have messed them up when we pulled the trany to fix the shifting problem, this scrued things up on my second test drive,I can only use 1st gear without causing the linkage to sieze up on me, having this fixed will be nice for testing.

The boost has to be escaping somewhere, I can't be sure the turbo is spooling, but I know for sure that it spins freely and has no shaft play. It has to be a pre-turbo exhaust leak or something to do with the wastegate which I have checked twice now to make sure it is closed. I even went as far as pulling the turbo to get a better look at things, everything seems to check out, but I'm not a expert and could have easily over looked something. If anyone else has any imput it would be greatly appriciated. It is extreamly frustrating to get so far and invest so much time to get hung up on somthing that seems like you put it together right the first time and the more I look at it the more it seems right. At this point anything besides "do a boost leak test" would be helpful. I just can't see a boost leak to causing no boost situation without anying noticable running problems. Even if I don't get the answer the input may lead me to think of something or look at this in a different way. Maybe I'm just hung up on my opinion, for I can't seem to find the problem.
I noticed that I had a rip in vacuum line that runs from the j-pipe to the WG when looking things over again last night, not sure if I ripped it when I pulled the turbo this time, or when I started to pull the turbo,but never did, when I first encountered the problem. Originally the WG was all-the-way open. After closing it and doulble checking that all my lines were run right just to look them over again, it still wouldn't boost. This is when it was time to ask for advice. I may not have been lucky in the fist place, but with some of that well deserved luck that I havn't seen in some time . The WG being open to begin with and FINGERS CROSSED if I ripped the line before I went for a test after closing the WG this would have caused a NO boost situation if my knowledge is correct. This would have caused there not to be vacuum on the WG and would have caused it to open prematurly under little pressure. All the lines were brand new so it would have been easily overlooked at first. I will hopefully get a chance take it around tonight or tomorow.

I'll get this thread updated when I get out to test it and hopefull I atleast get into boost. I know I have boost leaks and will probably encounter some aweful running conditions when i finally get there. Definetly need to get around to fixing them, not sure what the extent, but what DSM doens't have one or two especially on the first few test runs.

Thanks again,

Zach

 

[SBstar]

I'll think about more to mention, but for now just a little clarification. If your line to the wastegate had a hole or was disconnected it would cause an overboost situation, not a zero boost situation.

EDIT: Alright, a few more suggestions.

1: post a pic of your engine bay so we can get a look at it all hooked up currently. If something is hooked up incorrectly maybe we can spot it.

2. The actuator on your wastegate is one of those crappy ebay "adjustable" styles. I know we've covered the whole "wastegate is closed" thing, but it's still one of the most likely causes. With how the rod is currently adjusted it's possible it's not closed fully, ensure that if you disconnect the rod, fully closed is in the same position a with the rod attached. Also while you have the rod disconnected try pulling it, how hard is it to essentially pull it out of the wastegate actuator?

3. Help me out on this one, you only have 1st gear currently? Have you only had 1st gear throughout any/all tests you've done so far with zero boost? Alot of people have seen 1st gear no boost issues (or very low), I've never seen a true answer as to why, only boost leak test recommendations and others saying that it's normal (I'd say most of us see boost in 1st).

 

[zanderson]

I'll think about more to mention, but for now just a little clarification. If your line to the wastegate had a hole or was disconnected it would cause an overboost situation, not a zero boost situation.

Doesn't that vacuum pressure along with the stengh of the WG spring determin how long the WG stays shut? If I remember right, I may be wrong here, but isn't that line that you tee-off to put in a MBC?

I adjusted the WG with the arm still conected,I never disconnected it just turned the nut with a wrench till the WG was shut and it was tight. It's a POS ebay acuator, but the WG is closed. Not saying that it isn't giving way with little pressure do to malfunction in the acuator/crappy design. That picture is from when it was all-the-way open. I just got the turbo back on before work, where I am currently. I can snap some pictures when i get home in few hours if you would like.

3. Help me out on this one, you only have 1st gear currently? Have you only had 1st gear throughout any/all tests you've done so far with zero boost? Alot of people have seen 1st gear no boost issues (or very low), I've never seen a true answer as to why, only boost leak test recommendations and others saying that it's normal (I'd say most of us see boost in 1st).

On the first test run I made it through all 5 gears all-the-way to redline, then on the sencond go around my shifter siezed up on me. When I got it back to the garage I reliezed that one of my shift cables fraied and was haning up in the tube it runs through right by the trany.

 

[SBstar]

Gotcha.

As for the wastegate line. The spring tension is what holds the wastegate closed. The line going to the wastegate provides boost, not vacuum, which is what forces the spring down, moving the arm to open the wastegate. I'm guessing that if you simply adjusted the arm to have the wastegate closed with it connected, that may be your problem. If you bolt the wastegate arm to the compressor housing, then attempt to connect the arm to the wastegate flapper you actually have to muscle it a bit to almost "stretch" it onto the flapper. That way there is tension holding it closed. Tryadjusting it tighter and try pulling that arm to see what kind of tension is there.

Also where are you feeding the wastegate from? Meaning where are you getting your boost source for the vacuum line?

 

[nfernotalon]

Double check your timing along with ignition timing.

 

[zanderson]

Gotcha.

As for the wastegate line. The spring tension is what holds the wastegate closed. The line going to the wastegate provides boost, not vacuum, which is what forces the spring down, moving the arm to open the wastegate. I'm guessing that if you simply adjusted the arm to have the wastegate closed with it connected, that may be your problem. If you bolt the wastegate arm to the compressor housing, then attempt to connect the arm to the wastegate flapper you actually have to muscle it a bit to almost "stretch" it onto the flapper. That way there is tension holding it closed. Tryadjusting it tighter and try pulling that arm to see what kind of tension is there.

Also where are you feeding the wastegate from? Meaning where are you getting your boost source for the vacuum line?

I'm not sure where I'm tap at for the boost gauge, it was like that when I bought the car. Waste Gates is definately closed, caused an over boost. Hit 25psi the other day! WOOOOOOO!!! The only thing I can think of is that it was the line from the j-pipe to the wastegate for thats they only thing that was changed. It had a good sized rip in it.

Double check your timing along with ignition timing.

Good advice, Mechanical timming is dead, not sure on the ignition timming. Tyeler18 brought that up also, we thought they ecu may be pulling timming or something.

I'm pretty sure it was just that line and originally the WG being open. I read somewhere along the line that line not being hooked up would cause boost problems. If anyone has any reasoning behind that I would be interested to know why.

As for the NO boost problem it is **RESOLVED**

Thanks SBstar for keeping up on this thread, and thanks to the rest of you who contributed.

Zach
1990 Talon TSi AWD
**NO LONGER naturally aspirated**

 

[HULK]

How is the car boosting now? I have the same problem with my 1G.
So what did you do to resolve the problem? You just changed the line from the wastegate to the j-pipe?