Fuel tank pump issue, level sender issue

[Collie]

Originally Posted by andrewwynn

He replaced the pump. Comfort start will not apply power to the pump until your turn the key.

I think he got the car running now just trying to get the siphon jet working so no more dead in the water at 1/4 tank

I actually came to a stop and posted this thread. I became confused after looking at the real OEM site and knowing my vehicle did not have any of the cross over hoses attached to my pump assembly as shown. When I opened the left side of the tank and saw fuel and another level sender and no type of pump I shut the door and slept on it. After reading your post you have confirmed my thoughts. That is that the return from the filter back to the left side assembly creates the pressure to transfer fuel left to right. I would like to know your thoughts that I have that possibly the right side level sender registers 1/4 to full, as it did when I manually moved it through it's range, and when it bottoms, the left side sender takes the fuel level from 1/4 to empty?

[wpoll]

Originally Posted by Collie

... I would like to know your thoughts that I have that possibly the right side level sender registers 1/4 to full, as it did when I manually moved it through it's range, and when it bottoms, the left side sender takes the fuel level from 1/4 to empty?

The full gauge reading is the sum of the readings from the two halves of the tank - it is not that one sender is part of the range and the other is another part.

If you unlock the cluster menu you can see the actual sender values in test #6: -









(pics all thank to Qsilver7)

[Collie]

Originally Posted by wpoll

The full gauge reading is the sum of the readings from the two halves of the tank - it is not that one sender is part of the range and the other is another part.

If you unlock the cluster menu you can see the actual sender values in test #6: -









(pics all thank to Qsilver7)

Remind me how to get into that menu if you will. It's been awhile since I have done it. And your explanation of the sum of both sends the level to the display makes sense.

[wpoll]

Originally Posted by Collie

Remind me how to get into that menu if you will. It's been awhile since I have done it. And your explanation of the sum of both sends the level to the display makes sense.

This video shows it - but all you do is enter the BC (hold right button down until Test No. 01 appears), use right button to step to menu 19, press left button once, then enter the sum of your VIN numbers (using left button) and press right button.



https://youtu.be/iVabtlbhCdc

[andrewwynn]

RH drive puts the left/right backwards? I've always wondered what's going on there. Your tank isn't opposite is it? Electric pump left vs. right? The normal tank display is left/right/total and unless something is broken it's impossible to have 0 on the right and anything on the left.

The right will drop to about 1.5L when the left is about 27L. The left will drop to zero then the right will drop to zero. At that point about 3.6L left but the internal reading will be zero and DTE will stay zero.

[wpoll]

Originally Posted by andrewwynn

RH drive puts the left/right backwards? I've always wondered what's going on there. Your tank isn't opposite is it? Electric pump left vs. right? The normal tank display is left/right/total and unless something is broken it's impossible to have 0 on the right and anything on the left.

The right will drop to about 1.5L when the left is about 27L. The left will drop to zero then the right will drop to zero. At that point about 3.6L left but the internal reading will be zero and DTE will stay zero.

There's not much swapped over in the LHD/RHD versions - just the driver controls mostly. The signal and wiper stalks aren't even swapped over for the RHD (good thing I have an auto, or changing gear and operating the signals while cornering, all with the left hand, would be a mission!).

And the tank is identical on both LHD/RHD versions of the e53. If you are referring to the (Russian?) video - maybe the car is an e39 - not sure.

What I do know is my own RHD e53 operates exactly as per all your research indicates for the LHD versions, in terms of tanks emptying rates etc.

Well, almost exactly. It seems that when pumping diesel fuel the electic fuel pumps last a lot longer and the o-rings don't seem to swell or distort as badly.

[andrewwynn]

I'm referring to this picture which I just noticed is attributed to qsilver. This cant happen without malfunction: left side less than right (other than when less than 1.4L).

[wpoll]

Originally Posted by andrewwynn

I'm referring to this picture which I just noticed is attributed to qsilver. This cant happen without malfunction: left side less than right (other than when less than 1.4L).

Yep - understood but I also don't know what car this image is from - could be another e39 etc. - Qsilver7 posts on a number of different vehicle forums/threads.

I think the e39 tank(s) work in a similar way to the e53 but the plumbing is a bit different. Not sure - hard to study as I don't have one and it seems no e39 forum has a resident ARW.

I should have searched longer to find an image I *know* to be from an e53.

[Clavurion]

Originally Posted by wpoll

Yep - understood but I also don't know what car this image is from - could be another e39 etc. - Qsilver7 posts on a number of different vehicle forums/threads.

I think the e39 tank(s) work in a similar way to the e53 but the plumbing is a bit different. Not sure - hard to study as I don't have one and it seems no e39 forum has a resident ARW.

I should have searched longer to find an image I *know* to be from an e53.

Most likely those previous cluster images are from E39 (or E38). It has a symmetrical saddle tank and the left side is almost totally transferred to right side when the tank is near half (in diesel models if the in tank pump is working correctly).

[andrewwynn]

E39 I've worked on and changed pump. It does have a saddle tank but does not have the deep well for the pump which is a big improvement for taking turns and hills.

In researching the e53 fuel supply found plenty of posts where e39 drivers would take a hard ledt turn to slosh fuel to the right side at the first sign of fuel starvation. That's really not going to work on e53. The trade off of the deep well is by the time that is dry there's no warning