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2006 Z4 3.0i Auto
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Discussion Starter · #1 · (Edited)
Hey guys new member here and im having an insanely annoying issue with my 2006 Z4 3.0i w/130k+ miles its been sitting ever since february and now it will not start at all. All lights and interior electronics turn on and work, engine will crank but wont fire up. Checked all fuses, spark plugs/ ignition coils/ fuel pump was replaced roughly 7 months prior. Fuel pump control module seems to be fine but im suspecting damaged wiring from completely stripping my interior, dash/ door panels & passenger seat included. Tried manually powering fuel pump by bypassing control module, it pumps but still doesnt fire the engine. Sprayed starting fluid in the intake and it almost started but died so i believe i have good spark & maybe compression too. Any suggestions before i get it towed to a real mechanic?? i’ll post updated pics of the damaged wires when i take some but here’s a few old pics of my build before i screwed it up (currently in the process of painting it black & gold, 2 tone)
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Does sound like a fuel delivery problem if it almost fired up on the starting fluid. Try not to throw any more parts at it, it's probably one simple thing if it was running when parked. Are you able to hear the fuel pump run? I would also check for pressure in the lines.
 

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2006 Z4 3.0i Auto
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Discussion Starter · #6 ·
Does sound like a fuel delivery problem if it almost fired up on the starting fluid. Try not to throw any more parts at it, it's probably one simple thing if it was running when parked. Are you able to hear the fuel pump run? I would also check for pressure in the lines.
Yes i can hear it running constant when i manually power it from the battery, however it still wouldnt start without the fluid so i might have no pressure or the filter may be clogged. I last filled it up with a quarter tank of 87 as that was all i had near me when i ran out of gas on the road… gas might have gone bad for sitting so long, idk
 

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If you can, loosen a fuel fitting and see if gas sprays out when you manually run the pump. If so, retighten the fitting and try starting the car with the fuel pump still manually powered. This will test whether the pump is cutting out during the starting circuit.
 

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Edit: Sorry you already mentioned the car wouldn't start with the fuel pump manually connected. If it fails the spray test, maybe pump is caviitating, try adding more gas to the tank.
 

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2006 Z4 3.0i Auto
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Discussion Starter · #9 ·
Edit: Sorry you already mentioned the car wouldn't start with the fuel pump manually connected. If it fails the spray test, maybe pump is caviitating, try adding more gas to the tank.
Thanks i’ll loosen a fitting and see if gas sprays 👍
 

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2006 Z4 3.0i Auto
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Discussion Starter · #10 · (Edited)
Hey guys new member here and im having an insanely annoying issue with my 2006 Z4 3.0i w/130k+ miles its been sitting ever since february and now it will not start at all. All lights and interior electronics turn on and work, engine will crank but wont fire up. Checked all fuses, spark plugs/ ignition coils/ fuel pump was replaced roughly 8 months prior. Fuel pump control module seems to be fine but im suspecting damaged wiring from completely stripping my interior, dash/ door panels & passenger seat included. Tried manually powering fuel pump by bypassing control module, it pumps but still doesnt fire the engine. Sprayed starting fluid in the intake and it almost started but died so i believe i have good spark & maybe compression too. Any suggestions before i get it towed to a real mechanic?? i’ll post updated pics of the damaged wires when i take some but here’s a few old pics of my build before i screwed it up (currently in the process of painting it black & gold, 2 tone) View attachment 1036712 View attachment 1036713 View attachment 1036714 View attachment 1036715 View attachment 1036717 View attachment 1036718
EDIT: so i took apart the fuel rail, manually powered the fuel pump from the battery, which i can hear running, and no gas sprayed out… sprayed starting fluid directly in the ports and the intake, car ran for a split second then died immediately so now i gotta figure if its the pump which was already replaced less than 9 months ago or if the fuel filter is clogged or if its a wiring issue which is most likely the case…
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2003 BMW Z4 3.0i 6-spd Manual
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You could of easily tested if there was fuel pressure from the Schrader valve on the fuel rail with a fuel pressure gage
 

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That's good info but I think you can rule out a wiring/electric issue for now as the fuel pump is running, just not delivering fuel. Plenty of fuel in the tank? I don't know if our cars are like this, but on some cars if you run the tank low enough to lose prime on the pump, you have to almost fill the tank to get the pump to prime.
 

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EDIT: so i took apart the fuel rail, manually powered the fuel pump from the battery, which i can hear running, and no gas sprayed out… sprayed starting fluid directly in the ports and the intake, car ran for a split second then died immediately so now i gotta figure if its the pump which was already replaced less than 9 months ago or if the fuel filter is clogged or if its a wiring issue which is most likely the case… View attachment 1037063
You can try putting gas in it, it may help.
 
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