which fuel injector is leaking?

[kevinkay]

Thanks.
YES, I get that geyser
But should that "geyser" pressure be help endless or after time does that gas go back to the tank and whats left is that "poof"?
Is there a psi it should hold (cant I use an old tire gage since I don't get any gas spray after time)?

My logic (which is often faulty) is telling me my starting issue is that pressure- because if I pause the key at #2 before start -its a quick beautiful start. If I roll the key fast from 0 -3(start), (like I have done for the last 12 years) on a cool/warm engine it struggles to start.

thinking out loud........my ignition coils are old/original and on my list for replacement. Maybe tired ignition coils need that extra gas pressure?

[RToth]

Fairly new to these myself, so forgive me if I am way off here...

Fuel pressure regulator or a check valve would be my thoughts. The system should hold some residual pressure for a while after shut down, any vehicles I have messed with have a bleed down test for the pressure at the schrader valve with the key off and it should maintain X amount of pressure for however long.

[g300d]

^my thoughts too.

Fuel pressure regulator is built into the fuel filter. Your leakdown may be occuring there?

[kevinkay]

replaced the fuel filter at the onset, but will re-vist the connecting lines and observe them at pressure.

after 15 min. rest after key at #2 (and pressure is defiantly built) at the schrader valve there is a minimal pressure just a "hiss" with NO fuel escapement.

[upallnight]

This is all conjecture on everyone part. You need to hook up a fuel gauge at the shraeder valve and see what kind of fuel pressure you have with key on engine off and key on engine running. In order to fix the problem, you got to know what is causing the problem. Throwing parts at it get to be very costly and very frustrating after a while. A fuel pressure gauge set is less than an hour of mechanic's time.

[Ricky Bobby]

Originally Posted by kevinkay

replaced the fuel filter at the onset, but will re-vist the connecting lines and observe them at pressure.

after 15 min. rest after key at #2 (and pressure is defiantly built) at the schrader valve there is a minimal pressure just a "hiss" with NO fuel escapement.

Put it as position 2 to prime the rail, turn off, and let it sit a few hours - if no dribbles from injectors (it would probably show up within an hour) -

The pressure at the rail should hold, it doesn't "relieve" itself - which is why this is a good test for a leaking injector.

[TiAgX5]

http://www.xoutpost.com/bmw-sav-foru...-question.html

[kevinkay]

after car was driven yesterday and sat all night I just checked pressure at fuel rail valve and its zero. - SO I do have a pressure issue??
(funny that car starts no issue at cold but hard at warm)

When doing my injector "test" yesterday I did not see any dribbles from the injectors, over the course of the day I kept pressurizing the system (key #2). I do not think my issue is at the injectors nor where the fuel rail is connected (I kept feeling for gas). It is not the elec. fuel pump as that is new, the fuel filter has been replaced. I do not have any issues of running out of gas at 1/4 tank (and I always run it low) so I dont think its the syphon pump.
I dont have any issues when the car is running, never see gas under the car. I do have to admit after pressurizing the system yesterday with the injectors pulled I did get a wifff of gas odor. Might also look through my bicycle tools for the tool to tighten a schrader valve?
And when I get time I think next to check the connections at the fuel pump as I think there are 4 of them them there.

THANKS for all the help!

[80stech]

The rail pressure should stay up. If injectors are not leaking then pressure must be leaking back somewhere such as regulator or fuel pump. Fuel pump being new does not rule it out.

[fmugur]

I had the same problem on my 4.4 m62 a while back. I couldn't figure it out which injector or injectors were leaking but I replaced them all and problem solved. Check this tread below.

http://www.xoutpost.com/bmw-sav-foru...njector-4.html