BMW E39d injector problem?

the merchant

My '02 525d is currently not starting :-(

Recently it had been getting hard to start when hot so I had is scanned with Solas and there were "pre supply pressure" codes showing up. I changed the pre-supply pump under the floor but that didn't help.

Now it's a non starter. The fuel pumps are running ok when I turn the ignition but when I turn it off I can see air rushing into the fuel pipes between the filter and the engine.

My gut feeling is that this could be a leaky injector but I haven't a clue how to go about checking them. Do I need to remove them all and send them away or can they be checked in the car? If I do need to remove them are they handy to get out of the head?

Any help appreciated!

crosshair1

What is the pre supply pressure and the rail pressure when cranking?

the merchant

crosshair1 wrote: »

What is the pre supply pressure and the rail pressure when cranking?

I don't have that data I'm afraid - I was away and a mate hooked it up to Solas. Before it stopped running and was just hard to start when hot he scanned it and the pre supply pressure was 4.2bar while running but not sure what it was exactly under cranking other than that it was "low".

crosshair1

Pre supply pressure must be over approx 4 bar (from memory), and rail 200ish bar on cranking, otherwise the injectors wont be triggered.
You need to see if either or both are low before getting hands dirty

the merchant

I believe they are low as they have thrown up the "pre supply pressure too low under cranking" code, i just haven't got the figures.

Also any ideas on why the fuel lines fill with air as soon as the pumps stop running? This is also what's leading me to an injector issue.

crosshair1

You need to find out if either or both are low as this will determine if you need to look at the priming or high pressure side as the cause of the non start.
The fault code could have been from 5 years ago, who knows?
You could get a leak off test done while cranking, if you dont have access to the kit for this then you're best off book it in with someone who knows how to test these systems. (its usually a hell of a lot cheaper than guessing which part to replace)

the merchant

Thanks crosshair1, I do appreciate it.

I know that the fault codes are brand new as he cleared them and tried to start the car. I don't have access to leak down test gear - I have heard you can make them up with water bottles and some rubber hose but I really don't want to do down the mickey mouse route :-)

I think the car's next journey will be on the back of a lorry, I just want to bring it to the right guy who'll diagnose it correctly. I can throw parts at it myself!

b165

I had the exact same problem last week with my 02 E39 530d, my mechanic done a leak off test you just need the car to crank for this and straight away saw injector no. 5 was leaking. It cost me €211 for a refurbished injector and it fired up straight away after replacement. Starting no problem now:)

crosshair1

The fault code for pre supply pressure will not be caused by a leaking injector, if you have an injector causing low rail pressure and as a result not starting the fault will be something on the lines of "0190 rail pressure on crank too low" this is from memory and may not be 100%.

If your pre supply fault returns then the issue is not with the high pressure side.