Fuel accumulator

[sinbin5t]

Originally Posted by msh

It doesn't matter really - there are heavier restrictions in system, like fuel filter, and you won't feel it in any way, unless, maybe, running some very powerful 10vt engine still with K-jetronic, and only then on full boost approaching redline...

Just the man i wanted to make a reply, so maybe you could help me decide if i need the accumulator or not on the type 43 200 10v turbo i have, or should i not bother with it, i got hold of one last year.

[msh]

IMHO if the engineers have decided that it needs to be there, and you have working one at hand, use it. If you would have just faulty one, that would be good reason for not to use it...

My previous and likely last KE-jetronic powered cars were B3 2.0 8v and B3 2.3 10v - on first one without accumulator I experienced some small strange things, but that was probably because of fuel pump. On A90q it was fine, also when for some time it was disconnected. If the A90q will run again, it will probably lose accumulator, but just because it won't contain KE-jetronic anymore...

[sinbin5t]

Originally Posted by msh

IMHO if the engineers have decided that it needs to be there, and you have working one at hand, use it. If you would have just faulty one, that would be good reason for not to use it...

My previous and likely last KE-jetronic powered cars were B3 2.0 8v and B3 2.3 10v - on first one without accumulator I experienced some small strange things, but that was probably because of fuel pump. On A90q it was fine, also when for some time it was disconnected. If the A90q will run again, it will probably lose accumulator, but just because it won't contain KE-jetronic anymore...

Those were the lines i was thinking along msh, thank you for taking the time to reply to my question

I hope the A90q runs for you again.

[simons2]

Originally Posted by Gaz

Unless you are driving long distances all day with lots of stopping and starting all the time, I don't think you will notice much of a problem without it fitted.

As a side point, would fuel flow be any better without it fitted? Seems to me that removing it would be one less obstacle/restriction in the system.

Fuel supply/flow is not affected by the FPA whether fitted or not, its affected by the warm up regulator.
I bought a new one 2 months ago off ebay £75 delivered. There are many oem numbers and some that cross over.

[sinbin5t]

Originally Posted by simons2

Fuel supply/flow is not affected by the FPA whether fitted or not, its affected by the warm up regulator.
I bought a new one 2 months ago off ebay £75 delivered. There are many oem numbers and some that cross over.

Wish i knew more about this stuff, only know what i read

Do warm up regulators just go duff or can they be sorted ? Is it possible to do a test by unplugging it ?

[M4rkp]

The electrical connection on the WUR is for a heating element inside it, so disconnecting it could prove inconclusive - you really need to measure fuel system pressure and then control pressure to determine if the unit is faulty or not - if you remove the WUR from the block and turn it over you will see a blanking plate, underneath this plate is a grub screw which alters the amount of travel that the needle valve makes, therefore affecting control pressure of the metering head.
All of the Bosch WURs are basically the same - they are just set to different pressures for different vehicles -On my quattro I am running a WUR taken from a Golf - I have altered the grub screw to give me optimum control pressure at full working temperature.

[sinbin5t]

Originally Posted by M4rkp

The electrical connection on the WUR is for a heating element inside it, so disconnecting it could prove inconclusive - you really need to measure fuel system pressure and then control pressure to determine if the unit is faulty or not - if you remove the WUR from the block and turn it over you will see a blanking plate, underneath this plate is a grub screw which alters the amount of travel that the needle valve makes, therefore affecting control pressure of the metering head.
All of the Bosch WURs are basically the same - they are just set to different pressures for different vehicles -On my quattro I am running a WUR taken from a Golf - I have altered the grub screw to give me optimum control pressure at full working temperature.

Thanks for the reply Mark
I am confident the WUR will be the same age as the car (37 years), can this part dry up the same as a fuel distributor ? or perhaps just go faulty suddenly ?
If this happens can they be sorted or is it a replacement that is needed ?

[jimh]

The main purpose of the pressure accumulator is to hold the fuel in the injector lines at pressure after you shut down to prevent the fuel boiling in the lines causing vapour lock and resultant hot-start problems.
If you never get starting problems with a hot engine, don't worry about it, but you might get a problem after a long / spirited drive on a hot day...

[M4rkp]

Originally Posted by sinbin5t

if this happens can they be sorted or is it a replacement that is needed ?

There is a diaphragm inside the WUR which can tear - I suppose the needle float could stick especially if the system has been left devoid of fuel for some time.........The only real issue I have had is it going out of tolerance.....and that was due to me being a muppet!! - I was changing the hydraulic accumulator on my quattro and accidentally hit the top of the WUR where the two pipes connect.....this put it way out of spec, the bit where the pipes connect to is an interference fit and its position obviously affects the travel of the needle float as I mentioned in my earlier post.

Have a look at these people - I have used them before.

http://www.kmipetrolinjection.co.uk/

Mark

[sinbin5t]

Originally Posted by jimh

The main purpose of the pressure accumulator is to hold the fuel in the injector lines at pressure after you shut down to prevent the fuel boiling in the lines causing vapour lock and resultant hot-start problems.
If you never get starting problems with a hot engine, don't worry about it, but you might get a problem after a long / spirited drive on a hot day...

Great explanation there jimh, many thanks.