E89 2011 cranks but not start

[QTN]

Hi all, hope you can point me to some area to check.
Here is the story: I left my Z4 3.0i 2011 in the garage for the winter. When I started last week the battery was very weak and it would not crank nor start. I pulled my Honda Odyssey next to it with a jump cable, the car cranked but would not start. I have checked all the fuses under the glove compartment, number 70 and 4,5,11,12,14, 15, 16 all look good. I checked the 2 fuel pump relays, the one next to the battery compartment - I assumed these are the fuel pump relays - using a multimeter, looks good. :headbang: :headbang:

My questions:
1. where should I check next?
2. Where is the fuel pump in this Z4 30.i 2011 model? do I need to lower the fuel tank to get to it?
3. Should I replace the battery with the OEM BMW one or should I just grab one at Advance Auto Part - Diehard brand, a little more expensive but I don't have to drive 2 hrs to pick one up from BMW parts.

Please help. I appreciate all the help I can get to get my baby going again...
Best Regards,

Quang Nguyen
2011. Z4 30i. 58K miles. White exterior. Red interior.

 

[B21]

So the LPFP sits in the fuel tank..highly unlikely it’s failed..

A no crank can be many things..as we usually tell all newbies and those who deny reality..you need a decent BMW specfic code reader..with over 30 micro processors and over 50 sensors you’re just guessing..

Battery wise any AGM battery of 70ah or 80 ah that fits is ok..it will need to be registered and maybe coded (again why you need some decent s/w tools) but that’s a second order problem..

Could be a corrupted ECU as a result of the electrical abuse you inflicted on it..

 

[flybobbie]

Pull a plug and see if it sparks.
Place tissue over open plug hole see if it gets wet with fuel.

One or other must be missing.

Also i think BMW warn against jumping.
Better to charge battery only and then try and start.

 

[javis20]

Start with a fully charged battery. A dead battery and a fully charged battery doesn't result in full voltage battery. The low charged battery may be pulling the overall voltage down to where the cars computers won't work. I had this problem with a VW Passat. Tried jumping it for days. Cranks and no start. Then finally, out of desperation, I swapped batteries with my other car. It started right up.

 

[raymond.harper]

New battery and if she fails to fire, a can of Easy Start. https://www.youtube.com/watch?v=Ay3lZgDsJ8A&t=282s

 

[javis20]

That's a logical next step. Or check the fuel pump fuse and relay.

 

[chanlon1]

I had something similar on my E86 coupe.
Turned out it was a corroded ground strap. Had to call the AA out and they had it fixed in minutes.