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View Full Version : I think I have a vacuum leak.


stu
01-24-2004, 01:40 PM
So my boost guage used to read at -16 at idle, but now it seems to read closer to -14. Anyway, when neutral, if I hold the throttle at let's say 2500rpm and hold it steady; the car will start to drop the revs, and then bring them back up to where you are holding it at.

So, you hold the throttle at 2500, then the needle goes back and forth between 2500, 2000, 2500, 2000, etc. I've tried this as high up as holding it at 4000 rpm, and it does the exact same thing, only a little slower. Also, I noticed that even when I'm driving, if I push the clutch in, and hold the gas, I can repeat the problem.

Other Symptoms:
When driving, the car stutters all the time when going from zero/light throttle to light/medium throttle. I originally thought that this was from having my SAFC tuned wrong, but now it's looking like it's something else. Does this sound like a vacuum leak to you as well?

P.S. I basically molested a bunch of my vacuum lines when installing my boost guage, but this never started until the fuel pump, and injectors were installed. Co-incidentally (or maybe not) I took the dash pot off and made a block off plate the night before.

Anyway, I was looking at my lines and noticed that some of the plugs I made were a little loose. I tightened and basically un-ghettoed all my lines and still have the problem. So I suspect the dashpot block off plate has a leak (I just put some gasket stuff on it last night, but didn't let it set for very long). What do you think?

CSMsi311
01-24-2004, 01:48 PM
i have the same problem.. but it happens randomly even after i got it tuned.

stu
01-24-2004, 02:26 PM
Hmmm, weird huh? When I first installed my boost guage it didn't do that, but after I took the dashpot off it did. So I'm leaning heavily towards that. The only other thing I can think of, is that my boost guage is sharing a vacuum source with my map sensor. Tobi told me that I'd need to move it when I finally go turbo, so I didn't think it'd be an issue now.

Weston
01-24-2004, 02:47 PM
jeez... mine's like -18

stu
01-24-2004, 02:52 PM
Mine will go to -18 when I let off the gas, even if I just rev it while in neutral. It used to stay at -16 when idling, but now it's at -14. That is a definit sign of a vacuum leak right?

Weston, what does your SAFC read in vacuum? Mine reads like 590-600's when idling.

Weston
01-24-2004, 03:51 PM
-575 on the AFC and -18 on the gauge. If I rev it up and let off of the throttle, the gauge will go to around -22.

HONDA GHANDI
01-24-2004, 10:02 PM
Bring it by sometime, I have a sure way of finding vacuum leaks. But yes it sounds like a leak.

ryanman
01-24-2004, 10:38 PM
Stu your car is turboed already?

stu
01-26-2004, 01:09 AM
No, but all my guages are functional. I get a boner everytime my boost needle flys up to zero. What I'll do is drive around slowly, not looking at the guage at all, then I punch it, and see if I can trick it into going past 0. It hasn't worked so far.

HONDA GHANDI
01-26-2004, 01:21 AM
Sort of how I tricked you into buying me lunch that one time. HAHAHAHAHA

Mario
01-26-2004, 10:20 AM
No, but all my guages are functional. I get a boner everytime my boost needle flys up to zero. What I'll do is drive around slowly, not looking at the guage at all, then I punch it, and see if I can trick it into going past 0. It hasn't worked so far.

:rofl: Nice job man. :D