12/84 325e fuel pressure

[Mike]

OK, I am reviving this old e that was stored for 9 years, and threw a new main pump at it, to get the car driving, and to my shop. That pump set me back roughly 80 bucks. The problem is, its loud and sounds pissed off, so, I tested fuel pressure, which was pretty unimpressive, but don't remember exactly, probably 25-28psi at idle. So, I pulled the intank one, (rotten as hell!) and got no results with my bench test.

Now, my question is whether the helper, intank pump, does run continuously or not just during start up? Should I expect after replacing this pump too, that my fuel pressure should get back around the 2.5bar/36psi spec?

[jlevie]

The in-tank transfer pump should run all the time the engine is running. If it is bad it will somewhat starve the external high pressure pump and could result in lower than normal pressure at the rail.

[Mike]

this is what I thought. So, how about those things that look like pressure regulators that are also in the fuel system, is it ok to eliminate them from the fuel system? Obviously keeping the actual pressure regulator that is on the fuel rail, of course. I'm talking about numbers 16 (absorber?) and 19 (absorber?) on this page:

http://www.realoem.com/bmw/showparts.do?model=1254&mospid=47308&btnr=13_0233&hg=13&fg=15

and number 14 (absorber), and number 20 (damping unit)

http://www.realoem.com/bmw/showparts.do?model=1254&mospid=47308&btnr=16_0172&hg=16&fg=15