fuel pressure test location

[ahlem]

I have a 1990 535i and wanted to verify the location to do the fuel pressure test. There are two hard lines just below the intake manifold on the driver's side. One appears to have an anti reverse-flow valve in it. (I made a really good looking jumper switch with fuse that works well). Do I tee into that line? downstream from the anti reverse flow valve? A photo would be greatly appreciated. My little rubber hose from the fuel pressure regulator was cracked but not leaking. I replaced it.

[whiskychaser]

I have a 1990 535i and wanted to verify the location to do the fuel pressure test. There are two hard lines just below the intake manifold on the driver's side. One appears to have an anti reverse-flow valve in it. (I made a really good looking jumper switch with fuse that works well). Do I tee into that line? downstream from the anti reverse flow valve? A photo would be greatly appreciated. My little rubber hose from the fuel pressure regulator was cracked but not leaking. I replaced it.

I think what you call the anti reverse flow valve is actually the pressure regulator-its connected to the fuel rail next to the bulkhead. You need to tee into the hose at the front end of the engine where it connects to the fuel rail. Its item 15 here:
http://www.realoem.com/bmw/showparts...47&hg=13&fg=15

[ahlem]

Similar but it's a 535.
http://www.realoem.com/bmw/showparts...32&hg=13&fg=15
Where does one tap into the line? Down low or up high, next to the fuel rail?

[whiskychaser]

Similar but it's a 535.
http://www.realoem.com/bmw/showparts...32&hg=13&fg=15
Where does one tap into the line? Down low or up high, next to the fuel rail?

Next to fuel rail is easiest for me but as long as you pick the correct side of the regulator it shouldnt matter.

[Dave M]

You can also us the outlet line from the fuel tank sending unit.

Dave

[ahlem]

Here is an update. The lower test location is much easier to access. I made the relay jumper switch w/fuse and tested my fuel pressure. 22psi should be over 46 psi per the manual (if I remember correctly). New Bosch fuel pump picked up today. I will install in the next day or so and hopefully the higher rpm hesitation face falling will go away. It would be just typical that I take out the old fuel pump and find 18 years of lint stuck in the pick up screen and didn't have to spend $260 for the new pump.

[ahlem]

Final resolution! I changed the fuel pump and noticed bearing material in the sump of the fuel tank and inside the old pump pick up screen. Finished cleaning out the metal flakes with a turkey baster, installed the new pump put it all back together and fired it right up. The crank twice to start symptom went away. The check engine light does not come on any more and the fall on your face is a thing of the past. One other thing is that my "fuel economy" indicator is much smoother and more aligned with the 22 mpg I get if my foot doesn't get heavy formerly it read 15.7 on the trip computer.

[Dave M]

Final resolution! I changed the fuel pump and noticed bearing material in the sump of the fuel tank and inside the old pump pick up screen. Finished cleaning out the metal flakes with a turkey baster, installed the new pump put it all back together and fired it right up. The crank twice to start symptom went away. The check engine light does not come on any more and the fall on your face is a thing of the past. One other thing is that my "fuel economy" indicator is much smoother and more aligned with the 22 mpg I get if my foot doesn't get heavy formerly it read 15.7 on the trip computer.

Congratulations,

I'll have my head in the gas tank changing my pump soon enough

Dave

[ahlem]

Congratulations,

I'll have my head in the gas tank changing my pump soon enough

Dave

Remember to squeeze both the tabs that release the fuel pump, (at least on the 535i). One was hard to see and had me puzzled for a couple minutes.
Be sure not to get your head stuck, gas fumes are hazardous to your health.