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Old 07-08-2007, 09:20 PM   #1
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Default ?Lowered Boost pressure-Shitty MPG's-Decreased Vac?

Hey Dudes!
Lola is a little sick.
About a month ago I noticed that the vac was sitting at 18 instead of the usual 20. My gas mileage has been steadily decreasing the past two months. I'm getting about 18 MPG around town. She is running rich when I go to simple boost. I have dropped boost by at least 3 PSI.
Do you think it is a vacumm leak, or that my PCV valve sucks, or that the turbo is failing?
I run stoich up to around 2500, and then it goes to rich when I go over 3000 RPM and stays rich.
I have no odd sounds from the turbo and the greddy kit has not been a problem for nearly three years. I had it set for 6psi by the way.
Should I look at the waste gate linkage and see if it is fucked up?
I'll go over the whole thing hopefully this week, but maybe someone could come up with an instant answer (magically).
Timing set at 12 if I remember correctly, with 2 point increment decreases with the Bipes to drop to 6 under full boost - So, I don't think it has anything to do with timing. Fuel system is clean, it's not the cat, no restrictions, air filter is clean, piggyback FPR vortech with stock greddy disk.
1)runs rich after 2500 rpm
2)loss of boost (3 psi)
3)decrease in vacumm (from 20 to 18)
4 shitty gas mileage (18 to 16 MPG)
5)doesn't burn oil
6)no smoke (black,grey,white) from exhaust
P.S. Maybe the water thermosensor sucks?
Maybe the waste gate is a little stuck?
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Old 07-08-2007, 11:31 PM   #2
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sounds like a good ol' fashioned vacuum leak, albeit a very slight one.

how is your idle?
any CEL's?
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Old 07-09-2007, 06:16 AM   #3
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yeah i vote on vac leak somewhere. Do you run any management? I cant remember. Just to be safe check compression and FP, as well while you are at it nothing like a complete check up for lola she probably just wants some attention.
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Old 07-09-2007, 09:37 AM   #4
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o2 clamp? maybe the switch failed open?

otherwise vacuum leak or something.
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Old 07-15-2007, 09:12 PM   #5
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I think it is all fixed (temporarily).
Bad prong (broken) on the CAS (possible fuel consumption problem).
Then when I was re-timing LOLA, low and behold - I noticed that I blew a hole in the pipe. My boost was shot from the hole in the pipe.
I read through Braineacks fix it threads and found that I should use either zip-ties or ductape.. I opted for Ductape as the temporary Braineack fix it. :gay:
Thanks Braineack!
Love,
LOLA
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Old 07-16-2007, 12:11 AM   #6
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Quote:
Originally Posted by LOLA - 92 View Post
I think it is all fixed (temporarily).
Bad prong (broken) on the CAS (possible fuel consumption problem).
Then when I was re-timing LOLA, low and behold - I noticed that I blew a hole in the pipe. My boost was shot from the hole in the pipe.
.......ctape as the temporary Braineack fix it. :gay:
Thanks Braineack!
Love,
LOLA
What pipe did you blow a hole in?
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