should you be able to blow through a fuel accumulator?

laura80 · 08-02-13, 11:01 PM

hi guys just wondering if anyone knows how you can tell if a fuel accumulator is faulty, ive had running problems for a while have been narrowing it down, took off the fuel accumulator & you can freely blow air through it, there is one inlet & one outlet when i blow through it there is no resistance whatsoever, like blowing through a large straw, does anyone know if this is knackered? would of thought there would be something ?? many thanks in anticipation

Cuppatea · 08-02-13, 11:19 PM

I may be wrong but from what i can remember the accumulator is there to hold the system pressure after the engine has been switched off, especially in the engine bay area.

Like a large non return valve which also has a damping effect on the fuel flow which is provided by the electric pump.

I'd like someone else to confirm this first though!

laura80 · 08-02-13, 11:37 PM

thanks for your reply yeah that makes total sense so there should really be some resistance shouldnt there, well see what anyone else comes up with thanks

Audi Derek · 09-02-13, 08:25 PM

As cuppatea has said he is spot on,
all that is in there is a spring and a diaphragm, as the pump pumps fuel so it pushes the diaphragm back and opens a chamber so that the fuel flows to the fillter/engine when the pump stops so the chamber closes holds the fuel in the lines (stops it from running back) makes for better hot start..

..

Micky · 09-02-13, 08:40 PM

when i had a knackerd one it back prussered into the tank and when cap was removed all the fuel pissed out all over the floor .look for signs of damp around the back of it by the screw .

laura80 · 09-02-13, 11:12 PM

thats great really appreciate all your replies im gona buy a new one then cheers guys :-)

Cuppatea · 11-02-13, 09:07 PM

Out of curiosity and for the benefit of others in the future, whats the symptoms its showing?

Cheers

laura80 · 11-02-13, 09:11 PM

well its been iffy for a while , starts perfect, then the revs peter out & it dies, can keep it running with foot on gas, runs fine but wont start at all when warm. starts fine cold, starts fine hot , but when warm no chance. hoping it will sort the bad idle out as well as the warm starting problem as have tried a million things . thanks again

09-02-13, 08:25 PM	#4
Audi Derek “Been raced and rallied” Classic Audi Club Member Join Date: May 2008 Location: Bridgwater Somerset Posts: 1,431	As cuppatea has said he is spot on, all that is in there is a spring and a diaphragm, as the pump pumps fuel so it pushes the diaphragm back and opens a chamber so that the fuel flows to the fillter/engine when the pump stops so the chamber closes holds the fuel in the lines (stops it from running back) makes for better hot start.. .. __________________ Vorspurng durch Technik (see it does work)

08-02-13, 11:19 PM	#2
Cuppatea Grown up member Join Date: Feb 2011 Location: Somerset Posts: 105	I may be wrong but from what i can remember the accumulator is there to hold the system pressure after the engine has been switched off, especially in the engine bay area. Like a large non return valve which also has a damping effect on the fuel flow which is provided by the electric pump. I'd like someone else to confirm this first though!

08-02-13, 11:37 PM	#3
laura80 Grown up member Join Date: Feb 2009 Posts: 71	thanks for your reply yeah that makes total sense so there should really be some resistance shouldnt there, well see what anyone else comes up with thanks

09-02-13, 08:40 PM	#5
Micky Mr Fifty Thousand! Classic Audi Club Member Join Date: Apr 2008 Location: Birmingham Posts: 8,738	when i had a knackerd one it back prussered into the tank and when cap was removed all the fuel pissed out all over the floor .look for signs of damp around the back of it by the screw .

09-02-13, 11:12 PM	#6
laura80 Grown up member Join Date: Feb 2009 Posts: 71	thats great really appreciate all your replies im gona buy a new one then cheers guys :-)

11-02-13, 09:07 PM	#7
Cuppatea Grown up member Join Date: Feb 2011 Location: Somerset Posts: 105	Out of curiosity and for the benefit of others in the future, whats the symptoms its showing? Cheers

11-02-13, 09:11 PM	#8
laura80 Grown up member Join Date: Feb 2009 Posts: 71	well its been iffy for a while , starts perfect, then the revs peter out & it dies, can keep it running with foot on gas, runs fine but wont start at all when warm. starts fine cold, starts fine hot , but when warm no chance. hoping it will sort the bad idle out as well as the warm starting problem as have tried a million things . thanks again