explain this part please.....
Joined: Mar 2006
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Car: 1973 Datsun 240Z/ 1985 S-15 Jimmy
Engine: Turbo LX9/To be decided
Transmission: 5-speed/T-5
Axle/Gears: R200 3.90/7.5" 3.73
Re: explain this part please.....
It's what the FPR uses to control uel pressure for different engine loads.
To be more technical, a vacuume referenced FPR keeps the delta fuel pressure the same over all engine loads.
To be more technical, a vacuume referenced FPR keeps the delta fuel pressure the same over all engine loads.
Joined: Jun 2000
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From: Enschede, Netherlands
Car: 82 TA 87 IZ L98 88 IZ LB9 88 IZ L98
Engine: 5.7TBI 5,7TPI 5.0TPI, 5,7TPI
Transmission: T5, 700R4, T5, 700R4
Axle/Gears: 3.08, 3.27, 3.45, 3.27
Re: explain this part please.....
Yes, you have to figure that the fuel pressure in the rail is not the effective pressure. It's simply the pressure relative to atmospheric. The issue is, that the engine only operates close to atmospheric at WOT. Anything but WOT and you have vacuum (actually pressure lower than atmospheric), this is the absolute pressure. Now, if you have a FP of say 43psi at the rail an the engine is operating at 10psi vacuum, or better a pressure of 10psi below atmospheric, the effective pressure would be 53 ps. Too much fuel delivery would result as the ECM relies on a constant fuel pressure. So, the vac referencing (which is similar/the same as boost referencing) keeps the EFFECTIVE fuel pressure the same throughout the intake pressure (vacuum) range
Last edited by Twin_Turbo; Sep 21, 2010 at 07:27 AM.
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From: Queens, NY
Car: 1986 Chevrolet Camaro
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Re: explain this part please.....
Wish I could give you rep points for an answer like that. Bravo.
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