Fuel Pump Question

Post here for mechanical and engine topics such as fuel issues, transmission problems, rough idle, exhaust, electrical issues, etc

Moderators: GRNSHRK, ron, bfons

Post Reply
User avatar
Boggie
Posts: 185
Joined: Wed Jan 31, 2018 3:57 pm
Location: Buckinghamshire UK

Fuel Pump Question

Post by Boggie »

Hi All,

So, today, after my engine rebuild I got the motor filled with fluids but it failed to start. After some process of elimination stuff I found the fuel pump fuse had blown. So, with fuse 11 duly replaced, the engine burst into life and I got it running up to temperature. All was OK but I heard the fuel pump note change and then the motor splottered and died. After a few minutes rest (checking the fuse and relay etc) I tried again and all was well, with the pump whirring and the M88 purring. However, the fuel pump is listed in my brain as definately suspect so I am looking to get a new one..

Now, I am easily confused (PTO on both sides of a piece of paper, 2 spades in the shed and asked to take my pick etc) but REAL-OEM list a SUCTION DEVICE (don't get me started) that is mounted in the fuel tank and quoted as a Pre-Supply Pump. Does this mean that the car has more than one pump? I cannot see anything obvious on the drawings...

Thanks,
Ian
1985 M635CSI
Classic Car and Bike Collector & Restorer.
User avatar
Soperman
Posts: 537
Joined: Tue Nov 25, 2014 2:44 pm
Location: London, UK

Re: Fuel Pump Question

Post by Soperman »

Many years ago, whilst running my first M635 as an impoverished enthusiast, I encountered a problem as a result of my only being able to afford to "fill" with £5 - £10 worth of fuel at a time. When accelerating or changing direction on very low fuel levels, the engine would cut out as it was momentarily starved of the dregs fuel sloshing around at the bottom of the tank. No such problems existed on the rare occasions I could afford to fill with more than a quarter tank.

If memory serves me right, the problem was diagnosed as a failed/faulty pre-pump located in the fuel tank. So, yes, I do believe there is more than one fuel pump. And if your problems coincide with low fuel levels, you might want to start looking there.
E24 M635CSi
User avatar
hornhospital
Platinum Member
Platinum Member
Posts: 2931
Joined: Sun Jul 11, 2010 6:46 pm
Location: Silverhill, AL
Contact:

Re: Fuel Pump Question

Post by hornhospital »

Boggie, yes, two pumps. A low pressure, high volume "lift" pump in the tank, and a high pressure, low volume external pump. Unless you're a purist, do yourself a favor and replace the two-pump system with one Walbro in-tank pump.
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
Pod
Platinum Member
Platinum Member
Posts: 4492
Joined: Tue Mar 16, 2010 8:32 pm
Location: usually in the barn, Kent, England.

Re: Fuel Pump Question

Post by Pod »

Hi Ian, Ken’s correct - there are two pumps as he describes. However, not all Euro cars had the in-tank pump, although I think all the “M” cars did.
User avatar
Boggie
Posts: 185
Joined: Wed Jan 31, 2018 3:57 pm
Location: Buckinghamshire UK

Re: Fuel Pump Question

Post by Boggie »

Thanks chaps!
I have managed to ID the lift pump but for the main pump does anyone know the part number for a decent make, such as Bosch please?
Cheers,
Ian
1985 M635CSI
Classic Car and Bike Collector & Restorer.
User avatar
Brucey
6 Series Guru
6 Series Guru
Posts: 10077
Joined: Fri Apr 09, 2004 7:17 am
Location: Cambridge, UK

Re: Fuel Pump Question

Post by Brucey »

do check for yourself but AFAICT
the current BMW number is 16141179232
the old BMW number is 16141178751
the old Bosch number is 0580464013 (or 0580464070)
and the new Bosch number is 69412

specs of some older bosch pumps (including ....070) here

http://www.binarysupplies.co.uk/TVR/Bos ... 0specs.pdf

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
User avatar
Boggie
Posts: 185
Joined: Wed Jan 31, 2018 3:57 pm
Location: Buckinghamshire UK

Re: Fuel Pump Question

Post by Boggie »

Thanks Brucey,

That seems to match up with what I see too. So, to replace the fuel supply system on my M635CSI I am going to need:

In-Tank Lift Pump
BMW 16141179424

In-Line Fuel Pump
Bosch 69412

In-Line Fuel Filter
Bosch 0 450 905 030
(BMW - 13329063165)

The last 2 are readily available but the lift-pump is proving elusive this side of the Atlantic. Closest I can find as being in stock is in Latvia! Can anyone recommend anywhere that may stock them please? I have been through 12 pages of Google so far...

Thanks,
Ian
Last edited by Boggie on Thu Mar 29, 2018 2:16 pm, edited 1 time in total.
1985 M635CSI
Classic Car and Bike Collector & Restorer.
daz635
Posts: 102
Joined: Sat Jul 20, 2013 7:26 am
Location: Brisbane, Australia

Re: Fuel Pump Question

Post by daz635 »

Schmiedman or Wallothnesch both in Europe though

Both around $290 US plus shipping

https://www.schmiedmann.com/en/catn-or?q=16141179424

https://www.wallothnesch.com/en/catalog ... 6141179424
'86 Euro 635 #1887204 Schwartz (086) Buffalo Schwartz Interior
Image
User avatar
jps635
Platinum Member
Platinum Member
Posts: 872
Joined: Sat Feb 27, 2010 10:50 pm
Location: NZ

Re: Fuel Pump Question

Post by jps635 »

Not that long ago my in-line pump started leaking quite badly so replaced that and shortly after, when the engine was out replaced the lift pump.

I purchased from Wallothnesch and it didn't come with the tank gasket, so might pay to check this first. (They did apologise and quickly shipped one out at their cost).

Would also recommend replacing all the hoses and clamps, including the breather hoses. i couldn't source the metric factory hose sizes locally so got these off-shore as well. Note when pulling the breather hoses off the expansion tank, the plastic hose tails are easily broken, so work these off carefully in a longitudinal direction without too much lateral wiggling.
'85 635csi JPS (RA2-66)
User avatar
Boggie
Posts: 185
Joined: Wed Jan 31, 2018 3:57 pm
Location: Buckinghamshire UK

Re: Fuel Pump Question

Post by Boggie »

Thanks All,

To my surprise the BWM genuine lift-pump was almost the same as the price for after market pumps and they had it in UK stock for next day collection. With a 10% BMW owner's club discount it came in at around £270 so I ordered it.

Cheers,
Ian
1985 M635CSI
Classic Car and Bike Collector & Restorer.
User avatar
Boggie
Posts: 185
Joined: Wed Jan 31, 2018 3:57 pm
Location: Buckinghamshire UK

Re: Fuel Pump Question

Post by Boggie »

Brucey wrote: Mon Mar 26, 2018 11:14 am do check for yourself but AFAICT
the current BMW number is 16141179232
the old BMW number is 16141178751
the old Bosch number is 0580464013 (or 0580464070)
and the new Bosch number is 69412

specs of some older bosch pumps (including ....070) here

http://www.binarysupplies.co.uk/TVR/Bos ... 0specs.pdf

cheers
Hi Brucey,

Do you know if the pumps the same for the M635CSI as the Non-M models?
1985 M635CSI
Classic Car and Bike Collector & Restorer.
User avatar
Sixracer1
Posts: 26
Joined: Thu Sep 12, 2013 2:29 am
Location: New Hampshire
Contact:

Re: Fuel Pump Question

Post by Sixracer1 »

I made the mistake I will mention so maybe another can learn. I accidentally ordered a 16141179425 pre pump instead of the earlier 16141179424 that fits my ‘85 M635CSi. Not compatible, what a pain. Now I have a nice new fuel level sending unit and the same poor fuel delivery. Oh well!
'85 M635CSi #64
‘08 535XiT 6sp
Sold '01 325XiT
(Formerly "Sixracer")
User avatar
Sixracer1
Posts: 26
Joined: Thu Sep 12, 2013 2:29 am
Location: New Hampshire
Contact:

Re: Fuel Pump Question

Post by Sixracer1 »

Oh, any tips on how you remove the in-tank pump?
Looks like it rotates to unlock. Which direction?

Edit:
https://youtu.be/ATmzI-ZN3gQ?t=4m29s
Last edited by Sixracer1 on Thu May 10, 2018 3:04 am, edited 1 time in total.
'85 M635CSi #64
‘08 535XiT 6sp
Sold '01 325XiT
(Formerly "Sixracer")
User avatar
hornhospital
Platinum Member
Platinum Member
Posts: 2931
Joined: Sun Jul 11, 2010 6:46 pm
Location: Silverhill, AL
Contact:

Re: Fuel Pump Question

Post by hornhospital »

Lefty loosey, righty tighty.

CCW to remove, CW to install.
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
Post Reply