E39 530i intermittent non start

Just waiting on a fuel pump as they were on back order from Bosch. (Bosch apparently are partners with TI Automotive/Walbro who are the OEM). They're due early April, so fingers crossed. I only want to do the job once and not in a rush so went with a new one rather than second hand.

As a side note it's so annoying all these places that list things as being in stock on their websites but in reality they just don't ever update anything, so you order it and a few hours later you get an email saying they don't actually have it. Seems like it happens for most things I order for this car now.

Got all the bits. LCM swapped back in and all lights work fine, scored a genuine new crank sensor for £40 on ebay so swapped that once i realised how easy it was to get to.

Doing the fuel pump related bits now. Can't for the life of me find the fuel pump relay. It's not up behind the glove box, have had all that out and the only relay there is for the horn. Dropped the cream plastic carrier down which contains two modules and a junction box and there are no relays above it.

There are two green relays on the fuse box above the battery. Removing both of these does not stop the car from running. Think they are for the heated rear screen and parking sensors possibly.

Am now stumped.

Thanks yes have spent the last hour trawling forum threads! It’s a dec 2002 530i saloon so it should be behind the glovebox. But it isn’t.


Boot relays above battery:



Stuff behind glovebox:

Got it to replicate the no hot start issue. Could hear a relay ticking (have removed rear seat to hear/feel what fuel pump was doing). Fuel pump wasn’t priming.

Tracked the ticking down to the e-box under the near side pollen filter. There’s definitely a relay in there that isn’t latching.

Can’t get two of the bolts holding the lid of the box off though. The moulded in nuts are just spinning. Ffs

Small amount of progress. Levering technique worked well

Just got to identify what all the bits are

For reference the fuel pump relay is the blue one in the e-box part number 6915327.

Not a green one behind the glove box like everyone says! (Not on this car anyway)

Yes

Swapped fuel pump and although it seems to run smoother it still doesn’t start when it’s warmed up.

That blue relay clicks (I haven’t replaced that yet) and the gauges do this, lights on and temp gauge in red (it’s not overheated).

I think there is something more sinister going on.

When it’s running it’s perfect but there’s some issue that seems to be stopping the ecu coming on when the car is warmed up.

If you leave it 5-10 mins it will start and run fine.

Actually I think the clicking blue relay is the DME relay, still no idea where the fuel pump relay is but don’t think that’s the issue.

I found this:

https://m.youtube.com/watch?v=hk1HjL8PTRg

That’s the exact symptoms mine has. Looks like a possible DME issue.

So I think there are two options- repair the existing ecu or find a 2nd hand one and get the info from the old one cloned on to it so it can talk to the ews.

Need to find someone reliable who can do the programming.