How exact does fuel pressure need to be?

[joostvdw]

How accurate does the fuel pressure need to be? If it's .2 bar off on 2.5 bars total, is this bad? I'm thinking it can't be that accurate, because it is, I'm screwed with my ebay special fuel pressure gauge

[Rev. Dick Deluxe]

It depends what your trying to do. If your trying to diagnose a non start fault then .2 bar isnt going to be your problem. If your fine tuning your mixture strength then you need to know the exact rail pressure.

[joostvdw]

Sept 4, 2011 21:21:07 GMT Rev. Dick Deluxe said:

It depends what your trying to do. If your trying to diagnose a non start fault then .2 bar isnt going to be your problem. If your fine tuning your mixture strength then you need to know the exact rail pressure.

good point

I'm trying to determine if the fuel pump and/or fuel pressure regulator are still within spec and working like they should. This is important because the ECU doesn't have a O2 sensor so when the fuel pressure drops it starts to go lean and as you probably know, that's bad on a turbo charged car

[Rev. Dick Deluxe]

Are you taking into account the vacuum signal on a running engine or is this with the vacuum disconnected?