Boost guage, no boost, weird numbers. Help!

[Thor06]

Well, we got Mikes boost guage (Autometer Cobalt 30/30, mechanical, very sexy when it lights up!) on Friday and finally got to get it in today. We tapped at the fuel blah blah solenoid (cant exactly remember what its called) and ran the vac tube through the firewall to the guage. We then realized that we need something to mount the guage to. This is where our little-town-in-northern-minnesota creativity came in . Heres some pics:









Dont worry, this is by no means permanent . The guage pod will be here this week, we just wanted to get it on and see that it works. So we eagerly start up the bastard to see it in action. At idle it read 18 vac, so we let it warm up some then revved it a few times. We put it to 4k, 5k, and 7k and it never even got to 0! It would get to ~10 vac and stay. It was a cold day and the hood was open and when Mike revved I could see shitloads of smoke coming out from under the manifold heat shield. Can someone please they WTF is wrong with this god damn DSM now? (besides the coolant leak we found today while Mike and I were revving and checking to see if it would boost )

[defiancy]

Originally Posted by Thor06

d. Can someone please they WTF is wrong with this god damn DSM now? (besides the coolant leak we found today while Mike and I were revving and checking to see if it would boost )

Did you guys try taking it for a drive if you can? I don't think my gauge boots at idle. hold on one sec I'll go check and edit my post.


Yeah I just got in my car and revved it. It doesn't show boost at idle. And I know my guage works. So before you freak out try taking it for a drive.

[clipsekid99]

Ya, you won't see it read boost at idle when you rev it. But mine does go all the way to 0, when I rev though. Are you sure everything is hooked up right and no leaks in the lines?

[crunchymilk55]

the 18 vac is perfect, shows the motor is doing well

Take a pic of where you tapped it. Also, if you used the crappy plastic hose it came with, it might be pinched or bent somewhere. I got sick of that piece of crap (I actually melted mine), so I bought the autometer copper wiring for like 10 bucks. Problem solved.

[Thor06]

Yeah we used the teflon tape on the one thing on the back of the guage and checked the connections on the T fitting and guage to make sure they are pushed on good. That exhaust leak was pretty hardcore, now that I know it wont read boost when we are staying still, we'll take it for a drive. 18-20 in hg vac at idle though, sounds pretty extreme doesnt it? We parked it for the night because we thought there was something majorly fucked up, we'll take a drive tomorrow and see whats up. Could the hardcore exhaust leak cause the really high vac numbers? One of my friends is in school to be an automotive machinest and will resurface the exhaust manifold for us for free or cheap so hopefully it will work until we can get a new one later. Thanks for the help guys.

EDIT: Whew, I feel a lot better, thanks crunchymilk55. I just talked to Mike, he said he thought it hit 0 when he revved. We'll see tomorrow, thanks again guys, its really sweet to have so much support behind us when we are working on this car!

[defiancy]

Originally Posted by Thor06

Yeah we used the teflon tape on the one thing on the back of the guage and checked the connections on the T fitting and guage to make sure they are pushed on good. That exhaust leak was pretty hardcore, now that I know it wont read boost when we are staying still, we'll take it for a drive. 18-20 in hg vac at idle though, sounds pretty extreme doesnt it? We parked it for the night because we thought there was something majorly fucked up, we'll take a drive tomorrow and see whats up. Could the hardcore exhaust leak cause the really high vac numbers? One of my friends is in school to be an automotive machinest and will resurface the exhaust manifold for us for free or cheap so hopefully it will work until we can get a new one later. Thanks for the help guys.

18-20 is great vac. It's were my car idles at so, no it's not high vac numbers it's good vac numbers. And generally an exhaust leak won't cause a boost leak or bad vac numbers. Your exhaust will just sound very crappy.

[97GSTspyder]

i swear i'm going to make a 6 hour writeup on why a car won't produce boost when revving in neutral! lol

[crunchymilk55]

17-21 vac is perfectly normal, actually really good.

For the exhaust leak start with the simple stuff. Have you checked the gasket? Any cracks in the manifold? I believe the 1g manifolds crack very often, that would explain it. If you really feel like finding that leak, buy some seafoam and throw just a bit in a vac line. (the full thread is on tuners, just search for "seafoam works") This will cause smoke to come out your exhaust (ALOT), but if you have an exhaust leak it will pinpoint it out to you perfectly.

Also, I don't know about 1g's, but i know a bit about manifold leaks on the 2g (heh, I had them all),

[AbsoluteGTR]

Hey Thor06, much respect for always helping out your friend! Its hard to find a good decent friend these days!

But you know what I say!....I think its time for you to get your DSM, then you will be a happy man!

[crunchymilk55]

yeah Thor needs his own DSM

DSM's turn drivers into mechanics

[defiancy]

Originally Posted by crunchymilk55

yeah Thor needs his own DSM

DSM's turn drivers into mechanics

99% of my mechanical skill comes from working on my dsm. I can explain complex turbo systems to someone, but yet I fail to grasp the simple concept of algebra. Ahh it's great.




Well thor will be able to enjoy the fruits of his labor when his friends dsm gets done. hehe

[sganc4life_4]

I actually get about 22 vac, but thats probably because of where i live, in FL it was a bit lower

You dont boost at idol because theres no pressure/load on the motor for boost actually build.

[Thor06]

Wow a lot has happened since I left! I just went to work and took Mikes car for a drive. He babied it the 3/4 of a mile to work thinking there was something really wrong. Well, I let it warm up a bit and took it out. We dont have the backlights hooked up because the guage pod is on its way and didnt want to get everything hooked just to take it down later. After monkeying around for a while trying to figure out how to shine somelight on the guage (cell phone) I finally took a good hard pull. I have one word.... DAMN. You guys are right, I need my own! I drove it up about 4 hours from Minneapolis, MN when he bought it because it had shitty (basically no) brakes and he didnt know manual that great, but he wouldnt let me spool it. Oh did it spool tonight . I couldnt get many good numbers, but it idled at ~18-20 vac, and it spooled pretty quick. The only gear I got a good spool read in was 5th from a ~45mph roll. It hit 11 psi at 2700-2800 rpms.

Tomorrow after school that heat shield will come off and we will try to see why its smoking. Spool seemed pretty quick and I almost wonder if the coolant leak was somehow getting over onto the manifold and burning off.

I would have to agree, most of my knowledge of cars comes from this one. I took auto mechanics and advanced auto mechanics in school, but most of the problems I fixed the teacher just told me exactly what to do, and I did. Now when my good friend Mike gets a car with more leaks than cylinders in the engine and no breaks, you learn a little quicker. A Haynes manual and you guys have taught me lots about this car in the past two months and saved him lots of money, and I REALLY do appreciate it. I would definately have to agree with boyertownMidnight, there sure is a lot of "DSM love!" Thanks again everybody!

[Gsx_hooptie]

Lot of good info in this thread. Awesomeness. Your vac is good, your boost could be a little higher, and I agree that you definitely need your own DSM.

I'd make sure coolant isn't burning off, like you said, then check that the manifold isn't cracked like crunchy said. Then look into your gaskets. If you're really losing exhaust your turbo won't spool correctly. I also imagine you'd smell something amiss in the cabin at speed, but I could be wrong.

Your gauge is also the hotness, and I admire your ghetto-rigged gauge box. I know I don't need to say this, but I'd get the real deal soon.