Bimmerfest - BMW Forums - View Single Post - Where is the M54 fuel line schrader valve (to test lean conditions fuel pressure)?
View Single Post
Old 10-11-2011, 09:55 AM
bluebee's Avatar
bluebee bluebee is offline
Seek to understand,^Value
Location: San Jose, California
Join Date: Mar 2008
Posts: 25,236
Mein Auto: 02 BMW 525i M54 auto 130K
Originally Posted by JimLev View Post
fuel injection rail
Hi Jim & RDL,

This is embarrassing...

I 'had' searched the threads for the I6 Schrader valve; but kept coming up with V8 questions instead ...
- E39 (1997 - 2003) > Good replacement fuel pump 540i E39?
- E39 (1997 - 2003) > Fuel schrader valve 540i/6
- E39 (1997 - 2003) > How do I tet fuel pressure on 540i m62 V8?

And, of course, I had looked ... and looked ... and looked - in Realoem.

I now see 'my problem'.

Under #2 "cap" appears to me to be a 'fuel injector'; for the longest time, I had not seen the fuel system Schrader valve ... simply because it was not specifically 'listed' anywhere in this Realoem diagram (and because I didn't find a picture of the M54 Schrader valve in the I6 threads):
- Getting to know your M54 engine, a photo & identification guide to every visible part in the engine bay (1)

I've never worked with fuel injectors before though.

So, until I correlated your information with RDL's TIS below, I had not realized that the non-descript un-labeled un-numbered 'bump' on the front of the rectangular "rail" which is directly above the actual fuel injector 'was' the Schrader valve! [covered by a dust cap]

Originally Posted by rdl View Post
images from TIS will help
The TIS you kindly supplied is apparently also pointing to the same unlabeled 'nub' on the rectangular 'fuel rail' that JimLev pointed me to.

It would have been simpler if Realoem had labelled it as such; but I guess it's not a specific part you can replace on your own.

Going back to my pictures of my I6 spark plug DIY:
- Pictorial DIY for an M54 spark plug replacement on a 2002 BMW 525i E39 with 95K miles

With both your help, I now 'clearly see the fuel system Schrader valve in my own pictures!

Now I can further proceed to test the fuel system lean condition reported here:
- Does the order of the misfire OBDII DTCs diagnostic trouble codes actually matter (1)

What I plan on doing is borrowing the Autozone Actron Fuel Pump Diagnostic Kit CP9220A to determine if my lean conditions are caused by fuel deliver.

In addition, to look for vacuum leaks, I'll be looking up how to perform an intake system DIY 'smoke test' at home.

Maybe I'll ask these consultants ...
Attached Thumbnails
Click image for larger version

Name:	schrader_valve.gif
Views:	412
Size:	81.6 KB
ID:	296708   Click image for larger version

Name:	bmw_m54_fuel_supply_schrader_valve.jpg
Views:	28007
Size:	205.6 KB
ID:	296709   Click image for larger version

Name:	bmw_m54_schrader_valve.gif
Views:	12799
Size:	81.6 KB
ID:	296712  

Last edited by bluebee; 10-11-2011 at 10:32 AM.
Reply With Quote