- Joined
- January 22, 2007
- Messages
- 10,178
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- City, State
- selkirk, manitoba
- Year, Model & Trim Level
- 98 supercharged 347 sport
The fuel pressure regulator should regulate the pressure to 39.15 with no vacuum. With vacuum the pressure should drop 1 psi for approximately every 2 inches of vacuum. (this is because the conversion from vacuum measured in inHg to psi is approximately .49 to 1)
So if you had 20 inches of vacuum you should have 29 psi fuel pressure.
If it really only went from 42 to 39 that would mean you only have 6 inches of vacuum. Something doesn't add up with those readings.
You should fix this before any more tuning. make sure that you don't have anything hooked up to the vacuum line going to the fuel pressure regulator, like the PCV valve.
aaaaaaaah ffffffffffffffffff.......iretruck........
should this also be on a line by itself? i would have to look again for sure but this line is shared by my bypass valve on the supercharger, and it also goes to my vac/boost gauge