B2 fuel tank

jogi730 · 28-08-13, 08:41 PM

I am still experiencing fuelling problems with my car. The latest thought is that somehow the fuel tank is restricting flow.
Has anybody please got a schematic of the 85 B2 fuel tank, particularly showing the pick-up and return positions.
This information could stop the fuel tank having to be removed

Many thanks

msh · 28-08-13, 09:39 PM

If you have air compressor available, take off the hose from fuel pump, blow the air in and quickly place it back on pump. I'm experiencing similar problem - if I will run out of fuel, afterwards the tank will have some restriction which will cause some shaking @ WOT. The only strange thing - I cleaned my tank throughly a year and half ago. Unfortunately fuel outlet is on the opposite side to level sender, so when taking a picture through that opening, it couldn't be seen. Will have to put some webcam in in the future - currently it just makes me make sure I won't run out of the fuel

Coxy · 28-08-13, 09:42 PM

are you using the standard fuel tank with a standard fuel pump Chris?

jogi730 · 28-08-13, 09:44 PM

I have 2 Bosch 044 pumps working together.
They draw the fuel into a swirlpot but it sometimes sounds as if I am over-running the supply. Would still like more info, phot's from anyone that has cross sectioned one of these tanks or schematics if available

@ Coxy - Standard fuel tank

spink · 28-08-13, 09:52 PM

I know urq tanks have some kind of filter at the bottom.only way of cleaning/replacing it is to cut the tank open then weld it back up.not sure if n/a t85s have the same filter or not though

quattrostyle · 29-08-13, 07:08 AM

I had fuelling problems with my CQ type 85 Chris because the car stood for a couple of years without being used. Eventually put a clean tank in out of a 90 quattro type 89 and the problem seems to be solved.

However this might not be an answer to your question, your car also hasn't been used for a while and may suffer the same problem. The 90q type 85 is unique though as far as I'm aware and not interchangable with a newer item.

jogi730 · 29-08-13, 08:15 AM

Thanks chaps.
None of this is sounding good. Sounds like the tank may well have to come out. A schematic, some drawings or some photo's would still prove invaluable though.

Val · 30-08-13, 06:23 AM

Quote:

Originally Posted by spink

I know urq tanks have some kind of filter at the bottom.only way of cleaning/replacing it is to cut the tank open then weld it back up.not sure if n/a t85s have the same filter or not though

They all do have 2 filters under the car [k-jet engines]. One before pump and one after.

Hoyle · 30-08-13, 09:23 AM

I'd imagine they're still like the UR with a gauze inside. Also, I think Micky's running problems turned out to be a blocked/restrictive fuel return.

I considered a full tank derust and then POR15 tank seal refurb for my 80q, but in the end I decided that the tank sealer could block the internal filter. In the end I just rinsed it out with loads of fresh fuel until the flow was clear.

jogi730 · 30-08-13, 10:04 AM

Thank you kindly Val. THose pics could prove most helpful.
However, sounds like tank will have to come out to clean it properly

28-08-13, 09:44 PM	#4
jogi730 jogi Classic Audi Club Member Join Date: Dec 2007 Location: Luton, Bedfordshire Posts: 1,689	I have 2 Bosch 044 pumps working together. They draw the fuel into a swirlpot but it sometimes sounds as if I am over-running the supply. Would still like more info, phot's from anyone that has cross sectioned one of these tanks or schematics if available @ Coxy - Standard fuel tank __________________ 1985 Audi 90 quattro 20v turbo with some tweaks

29-08-13, 08:15 AM	#7
jogi730 jogi Classic Audi Club Member Join Date: Dec 2007 Location: Luton, Bedfordshire Posts: 1,689	Thanks chaps. None of this is sounding good. Sounds like the tank may well have to come out. A schematic, some drawings or some photo's would still prove invaluable though. __________________ 1985 Audi 90 quattro 20v turbo with some tweaks

30-08-13, 09:23 AM	#9
Hoyle 80q addict Classic Audi Club Member Join Date: Nov 2010 Location: North Wales Posts: 840	I'd imagine they're still like the UR with a gauze inside. Also, I think Micky's running problems turned out to be a blocked/restrictive fuel return. I considered a full tank derust and then POR15 tank seal refurb for my 80q, but in the end I decided that the tank sealer could block the internal filter. In the end I just rinsed it out with loads of fresh fuel until the flow was clear. __________________ My 80 Quattro thread

30-08-13, 10:04 AM	#10
jogi730 jogi Classic Audi Club Member Join Date: Dec 2007 Location: Luton, Bedfordshire Posts: 1,689	Thank you kindly Val. THose pics could prove most helpful. However, sounds like tank will have to come out to clean it properly __________________ 1985 Audi 90 quattro 20v turbo with some tweaks

28-08-13, 09:39 PM	#2
msh 4 ring whore! Join Date: Jun 2008 Location: Rucava, Latvija Posts: 3,816	If you have air compressor available, take off the hose from fuel pump, blow the air in and quickly place it back on pump. I'm experiencing similar problem - if I will run out of fuel, afterwards the tank will have some restriction which will cause some shaking @ WOT. The only strange thing - I cleaned my tank throughly a year and half ago. Unfortunately fuel outlet is on the opposite side to level sender, so when taking a picture through that opening, it couldn't be seen. Will have to put some webcam in in the future - currently it just makes me make sure I won't run out of the fuel

28-08-13, 09:42 PM	#3
Coxy 4 Ring Mafia Classic Audi Club Member Join Date: Jul 2007 Location: on the side of a hill in Shropshire! Posts: 28,215	are you using the standard fuel tank with a standard fuel pump Chris?

28-08-13, 09:52 PM	#5
spink Senior Member Classic Audi Club Member Join Date: Dec 2007 Location: yorkshire Posts: 1,525	I know urq tanks have some kind of filter at the bottom.only way of cleaning/replacing it is to cut the tank open then weld it back up.not sure if n/a t85s have the same filter or not though

29-08-13, 07:08 AM	#6
quattrostyle 4 ring whore! Classic Audi Club Member Join Date: Feb 2010 Posts: 2,188	I had fuelling problems with my CQ type 85 Chris because the car stood for a couple of years without being used. Eventually put a clean tank in out of a 90 quattro type 89 and the problem seems to be solved. However this might not be an answer to your question, your car also hasn't been used for a while and may suffer the same problem. The 90q type 85 is unique though as far as I'm aware and not interchangable with a newer item.