daem0n

Hey, I'm having a really tough time trying to figure out what this problem is. Boost pressure is constantly about -10 to -15 and never even reaches above 0 psi. The RPMs are hesitant anywhere from 1000 to about 5000, where it will go to the selected RPMs and then cut down every 3 secs for about 2secs...it will go down about 200 or 300 RPM and then back up, each time it does this, the boost level goes a bit lower and then back up when it's done surging. I'm thinking there is something wrong with the first turbo or maybe a boost line, but I don't really know where to look or what to look for. Can someone please help me? I've searched the forums and haven't found a situation exactly like this. Thanks a lot, -Joe

black99

If you never get above 0 psi, then you have major boost problems(maybe a leak?) or the line to your gauge is kinked or something of that sort. Do you get any "pull" like the turbos are pulling? The other problem sounds like it may be an ignition/vacum leak problem of some sort but I can't tell by the way you describe it.

It's probable that you have a broken vacum line somewhere and it's causing both of your problems though.

daem0n

Well, I'm pretty sure the turbos are working a bit, I mean I do get some pull, but it doesn't feel like enough. As for the boost gauge, I've checked the line and I can't find any kinks unless they're somewhere inside the dash paneling which I will check later, but I'm pretty positive that there is no boost because of the way the car is surging. I think I will check all of the vaccuum lines later on to see if one poped off or is broken. Also, I will check the ignition, but I'm not sure what to look for there...

black99

I don't know what to look for as far as ignition either. Ignition problems usually only happen in higher rpm ranges I think. At least that's usually for modded cars that need a aftermarket ignition. And a grounding problem could cause it to break up at lower rpms. I more than likely think there is a broken vacum line or something, somewhere.

daem0n

Hey Black, thanks a lot for your help. I'm going to check the vaccuum lines and I'm thinking about adding some grounds as well. As for anything else, I have no idea and am still open to ideas. Although, I've been testing it out a bit and I've restarted the ECU just in case it was in limp mode...it seems to have helped a bit, but now it still stutters in first gear a lot. I'm thinking it could be the ground.

daem0n

Has anybody seen this before?!!

Rotarius

Check the lines going to your MAP sensor by the firewall...

daem0n

just the vacuum lines?

black99

Yeah on the firewall on the drivers side, you'll see a small black box with a vacum line coming off the bottom, the box says "boost sensor", he wants you to check and make sure the vacum line is still attached. Personally I don't think this is your problem but I guess you could check.

daem0n

yeah, I checked the "boost sensor" there and the line is fine. I think I'm still missing some lines, but I've checked most of them...

daem0n

ok, I checked the nipples on the engine, both seem to have vacuum. I checked both with a gauge and they're both sucking about 17-20 of vacuum and they will move a bit up if the engine is rev'ed, when I say up, the numbers will be like 10-13 perhaps. What would cause vacuum? And where is the boost being created? It is solely from the turbos, like why is there vacuum? If an engine didn't have turbo's, would it create vacuum? Thanks a lot for all of your help guys, -Joe

daem0n

^ bump ^

daem0n

ok, I took apart the intake manifold, throttle body, air pipes, etc and checked all vacuum tubes, nothing yet. Everything seems ok, I don't know what to look for here...please help.

daem0n

ok, I have a couple more questions, I found these things in a couple old posts and was wondering how I could check all of the solenoids are working properly and how I can check if the check valves are all working properly. Thanks a lot, -Joe

weaklink

http://home.istar.ca/~dvandit/turbocharger.htm

daem0n

Hey guys thanks a lot for all of your advice. I took apart everything and checked all of the lines, I found a couple very loose and just re-did everything with a few small modifications. I can't tell what fixed it, but something did and I'm flying now. I was nervous about taking apart the manifold, but it paid off. Thanks again guys. And thanks Mark for the call, it helped too because one of the loose pipes was at the y-pipe.