Restrictive Performance DSC not Available P1338 Fuel Pump Driver Module
#21
05-27-2019, 03:31 AM
Senior Member
it will be the BMW's target pressure .
between the jags fuel pressure regulator and the fuel pump driver it will aim for 55psi .
as for the XJR & STR they too run on 55psi , and the higher fuel pressure you speak of is only for under boost conditions ,
and is achieved via a second fuel pump driver and a second identical pump that kicks in under boost conditions . to combat boost negating the fuel pressure at the injector .
between the jags fuel pressure regulator and the fuel pump driver it will aim for 55psi .
as for the XJR & STR they too run on 55psi , and the higher fuel pressure you speak of is only for under boost conditions ,
and is achieved via a second fuel pump driver and a second identical pump that kicks in under boost conditions . to combat boost negating the fuel pressure at the injector .
The pumps on the xjr like all x350's are fed with a PWM signal and are in effect variable volume with no fuel return line. The duty cycle is varied to both pumps to change fuel delivery as required by the rail pressure sensor/ECM.
The operation of the system is fully explained in the x350 technical guide, extracts of which are in post 7 of this thread;
https://www.jaguarforums.com/forum/x...adings-199546/
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axel1961
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