HELP! Stumbled Died, Now it Won't Restart..

[Best4x4xFAR]

Hoping someone has some ideas. I pulled out of my driveway an hour ago and as I was going up my street the car was surging under steady light acceleration. I turned around and came back. Full disclosure, I was really low on fuel, Trip computer said 6 miles to empty though, so its been worse.

Put about five gallons of gas in it from cans in my garage. Turned to on, started car, and it started right up, like normal. Idled for about 5-10 seconds, but before I even went to put it in gear, it stumbled once and died.

Now it won't restart at all (starter is spinning fine). Anyone have any Thoughts? I can't help but think it is fuel related. Dead Fuel Pump? Something I need to reset?

Trying to search the forums but not coming up with anything..

[bcredliner]

There are many potential causes. Since it started right after you added fuel and you ran the tank very close to empty, it could be that you picked up some trash at the bottom of the tank and clogged the fuel filter. If the fuel you added was really old that could cause a problem but usually it will still run. Suggest you start with a fuel pressure check. You can rent one at most auto parts store. Was it running normal the last time you drove it?

[Best4x4xFAR]

Originally Posted by bcredliner

There are many potential causes. Since it started right after you added fuel and you ran the tank very close to empty, it could be that you picked up some trash at the bottom of the tank and clogged the fuel filter. If the fuel you added was really old that could cause a problem but usually it will still run. Suggest you start with a fuel pressure check. You can rent one at most auto parts store. Was it running normal the last time you drove it?

Was running fine the last time it was driven. Fuel I put in is fresh (I keep a couple of stabilized cans in the garage for a portable generator, and swap them out about every 6 months or less. This load was a recent refresh).

I can't seem to hear the fuel pump run when I turn the key. Unfortunately the truck makes to many damn noises and warning charms at start-up, that its tough to tell, but I tried and couldn't hear it.

Interestingly enough, If I let it sit for 15 minutes or so and try again, it starts right up, idles for a couple of seconds and dies, then won't restart. Which makes me thin knot fuel pump, but I dunno right now.

Not in the greatest of moods right now. It couldn't have picked a worse time to do this (thanks Murphy). Its dark, snowing, and the truck isn't even in my driveway right now, its out on the street

Can't wait to try to trouble-shoot this in the freezing cold, on the side of the road..

[Best4x4xFAR]

Tried it again. sounded almost like a faint thumping noise from the backseat, but it started, and idled. Started counting, got to 18 and put it in reverse and backed it into my driveway, and stopped. Seem to idle normally for another 30 seconds or a minute. Just as I moved it from Reverse to Park, it died. Won't restart. Could it be something related to the gear selector? Never heard of that, but I'm grabbing at straws now. At least it is off the street..

[upallnight]

Originally Posted by Best4x4xFAR

Tried it again. sounded almost like a faint thumping noise from the backseat, but it started, and idled. Started counting, got to 18 and put it in reverse and backed it into my driveway, and stopped. Seem to idle normally for another 30 seconds or a minute. Just as I moved it from Reverse to Park, it died. Won't restart. Could it be something related to the gear selector? Never heard of that, but I'm grabbing at straws now. At least it is off the street..

Do you still hear that thumping noise? Most likely you have a dead fuel pump. Gasoline in the fuel tank is used to cool the pump. By running it down to almost nothing you are actually causing more wear and tear on the pump. Put a new fuel pump in and add another 5 gallons of gas. Sorry I don't know how many liter that will be but I never learn the Metric system and I'm too old to start right now.

[andrewwynn]

Originally Posted by upallnight

Do you still hear that thumping noise? Most likely you have a dead fuel pump. Gasoline in the fuel tank is used to cool the pump. By running it down to almost nothing you are actually causing more wear and tear on the pump. Put a new fuel pump in and add another 5 gallons of gas. Sorry I don't know how many liter that will be but I never learn the Metric system and I'm too old to start right now.

This is a myth. Especially with the x5. The fuel pump will be submerged completely down to about 2L (1/2 gallon of gas).

The x5 fuel tank when operating properly ONLY EVER has 8L or 10L (6 v 8 cylinder) gas on the right side of the tank once you have less than about 2/3 tank of gas. (E.g. there is no difference from the fuel pumps perspective from 2L and 98L of gas in the tank)

That said, the system that pulls the fuel from the left side of the tank and keeps the reserve tank (8L and only 8L) full has a few failure points.

➀ fuel pump weak doesn't supply enough pressure to filter/regulator (45% chance)
➁ jet siphon pump defective (45% chance)
➂ fuel filter/regulator problem (5% chance)
➃ some other extremely rare situation

Put in some gas at least 4-5gallon (15-20L) and enable test mode 6 on the dash. You should see over 1L when driving level. If the jet pump isn't working full power it needs some depth of fuel on the left side to help and your won't get full range: in my example i would run out of gas with 70miles to empty.

I replaced the fuel pump first and got little improvement in the reserve tank quantity.

I took out the jet pump and found an misplaced o-ring :





I replaced the o-ring and it helped a little but the second joint in pump was leaking like a sieve. There was no o-ring : I added an oring and and it solved the problem

[Clockwork]

Originally Posted by upallnight

Put a new fuel pump in and add another 5 gallons of gas. Sorry I don't know how many liter that will be but I never learn the Metric system and I'm too old to start right now.

i gallon = approx 4L
therefore 20L of fuel you recommend

[CapeX5]

I agree with upallnight. Has to be the problem. No fun in this weather. Good luck man.

[Best4x4xFAR]

Found this thread, seems to be very similar (almost exact) symptoms, and fuel pump replacement resolved it. So I guess I will be ordering a fuel pump. Want to pull the seat and check voltage on the terminals first, but if its there, and no noise, ordering pump.

Looks like Rock Auto has a Delphi Pump (full assembly with sender, etc) for $127. Ideally I'd go BMW OEM, but the truck is getting up there, and not sure how much longer I am going to keep it, so..

Any input on the Delphi replacement pump? Looks like Pelican Parts carries/sells the same one for $207..

[StephenVA]

Pump pressure testing time.