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Discussion Starter · #1 · (Edited)
Hi, all. Here we are with one more thread.

I bought my 330i 2001 sedan 3 months ago. I'm doing the maintenance step-by-step. hehehe... If I had money I would buy a brand new bimmer. :clap:

Today was the all filters + fuel pump + oil level sensor, that I bought from Bavarian Autosport. Easy to buy, fast delivery. I liked.

The oil level sensor was causing the oil -green- light to come up for seconds every time I started the engine. It was annoying. I replaced, and now everything is quiet.

The old Cabin Filter + Air Filter seemed to have the frame only, I mean, no more (black) paper on it. They looked too black, torn, ugly, and I think the people inside the cabin will breath much better from now on and the engine as well. :woot:

I've replaced the fuel filter + the fuel pump (the whole set = #16 14 6 752 499, that includes the fuel level sensor). So far so good but the pressure regulator (FPR) included on the fuel filter. Everything seems to be fine but the vacuum pipe.

The vacuum pipe that comes from "F" connector (elbow intake after MAF) to the FPR seems to do not work. There is zero of vacuum. It doesn't make sense.

So far I got, the fuel rail/line is about 3.0 bar constantly and when the car is idle or low rev (lower than 3krpm) the vacuum at that line (from "F" connector to FPR vacuum hose) is zero, I mean, with a vacuum gauge connected there is no vacuum at that pipe.

I've read tons of threads about this but I didn't get a CLEAR thoughts about this.


1) There is vacuum at the system, but NOT in the FPR pipe. Is that right?
2) The "F" connector is free to blow or suck air on my case. Is that correct? I didn't disconnect the F connector from the elbow to see if there is a sphere or something. I couldn't get a real drawing from realoem to see. Anybody got it?
3) Some threads say no need vacuum to FPR, others say it doesn't. Anyone there that really knows what is going on?
4) Some people say, the vacuum from the elbow to the FPR is need in low rev to "relieve" the pressure in the fuel injectors, hence higher MPG. The car could gain 1-3 MPG only with this. Please comment.
5) Other people say the vacuum goes from the FPR to the elbow.

FYI, my average MPG is no more than 18 MPG (13 L/100km or 7.7km/l). When I'm playing with her, it's about 14 MPG and driving as soft as I can, at 50-60 mph (85-100km/l) I get 25 MPG (max I got so far in 3 months). Is that normal?



Thank you.
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