New guy with a "new" car. No boost/stumble issue

[Smoothinto2nd]

Hey guy's. I just picked up my first Subaru. It's a 1993 Legecy SS.

I'm new to turbo cars so I'm not really even sure what to search for (thus my searching has not helped) so I figured I'd describe the problem I'm have the best I can.

At low RPM the car feels great. Up until about 3000 RPM when I'd expect the turbo to start to kick in. When hard on the throttle the car has a noticeable loss of power once the 3k point is reached. It sometimes even feels like it stumbles a bit. If I gradually accelerate the problem doesn't feel pronounced but I'm pretty sure I'm not giving the turbo enough pressure to even boost. If on the highway at or around 3000 and put my foot down I have little or no power (80mph is hard to maintain). The previous owner replaced all the vaccum lines on 04 and they all seem good. He kept the union in between the BCS and the Compressor outlet.

I can only find two things that seem like they could be the culprit if it is in fact a vacuum issue. A couple of the line don't seem tight... by that I mean they slide off pretty easily.Also the joint where the line from the bottom of the BCS connects into the intake resonator comes out.

Any ideas?

Thanks
~Ross

edit: awesome... my first post and I put it in the intake section instead of the turbo section.

[Legacy777]

Welcome Ross,

I'd suggest verifying all the vacuum lines are correct. You can verify them based on the diagrams in this thread.

http://bbs.legacycentral.org/viewtopic.php?t=15268

Beyond that, you may want to get a boost gague to see what exactly the engine is doing. That will help in diagnosing the problem.

I'll move your post for you

[Smoothinto2nd]

Ha I had a print out of that very diagram as I went over everything to make sure it was at least connected to what it was supposed to be connected to. It was awesome that you guys have that here on the site. But ya I'm going to go check again for the 4th time but everything looks to be in place.

I saw the vdo boost gauge write up in the library and am thinking about getting this one.
http://www.jegs.com/i/VDO/918/150063/10002/-1?CT=999

Thanks for moving the post

[biggreen96]

Looks like a good quality gauge to get you going. These boost issues are a bitch but once it's fixed you will be I'm a fan of telling people to do basic tune up stuff, I replace plugs wires etc etc its seems like every years or two to keep mine running smooth.

[brand]

Since you've checked all your lines, you might want to look for leaks in other spots. Intake manifold gaskets, TB gaskets, stuff like that. Also check your plugs and wires as suggested so you can rule out an ignition problem. Maybe if you're bored check out the turbo and inlet pipe as well.

Good luck and welcome!

[adema2626]

Is it a 5 speed or auto? Because to me it sounds like it could possibly be a clutch issue. That it starts slipping once you hit more then a few pounds of boost.

[Smoothinto2nd]

It's a 5 speed.

Unless these do something different than a normal car I don't think the clutch is slipping. When it stumbles it actually slows the car for a second. Also the engine speed stays where it should be for the speed/gear I have at any given time.

Also I just seafoamed the car and it seems to have possible eliminated the stumble I've been having. I got more smoke that I ever have from this car (170000). Considering I've done it to a number of toyotas and nissans with over 200,000 that actually is saying something.

But I still can't feel the turbo kicking in... working on the boost gauge.

[awdimprezal]

You cant feel the turbo because its a eeny weeny little turbo, there is almost no lag, there is just nothing there....

[Dynamic Entry]

yeah, it's small, and without opening up the breathing it is hard to notice

but

I had this same issue and power up has not fully solved it.


to the OP

tune up tune up tune up

even if your vacuum lines are good the advice will be plugs, wires, fuel filter, fuel pump, pcv valve, gaskets.....

some or all of it could make the difference.

[Smoothinto2nd]

I cleaned the maf sensor and around the throttle plate and it's made a world of difference. I have a feeling it was mainly that as it was BLACK when I took it out.

Now I just have an idle issue to deal with. It gets stuck higher than it should be... at like 2-2.5k. Then it drops down to about 600 and idles fine. It was tuned for running at 5000 feet and I'm at sea level now so that might have something to do with it. Time to search for idle fixes now!

[93legacylsleeper]

Seafoamed? I've been wondering about this stuff. How did you use it on your SS? Pour it directly into the throttle body? I just got an SS as well and i think it could use a little internal clean up!

[Smoothinto2nd]

My car was so bad at 170,000 miles that I actually had to do it twice (if you get smoke, there's still more to be cleaned).

You can't just pour it in or you'll stall the engine and potentially even hydro lock it.

I just bought a short section of vacuum hose at put it on the throttle body at the location of line I on the diagram above and here. http://www.surrealmirage.com/vrg3/vacuu ... vacuum.png

You'll make your life a lot easier if you pour the seafoam into a cup or bowl so you can have the car "sip" it through the vaccum line. It will also be a bit easier if you have someone else in the car holding the RPM at about 2500.

[93legacylsleeper]

Sweet my Car is at 200000 so Im guessing there's gonna be a tinge of smoke hopefully no fire dept. Thanks for the info. Oh yeah and rock on for having an SS in the bay area i don't feel so lonley...