07-08-2007, 08:20 PM
Join Date: Oct 2004
Location: SWAMPS OF FLORIDA !!!
Total Cats: 0
?Lowered Boost pressure-Shitty MPG's-Decreased Vac?
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?