Fuel Valve To Stop Fuel Retreating From Engine

[Squirrelofdoom]

Hi guys,

Got a problem with the S3 at the moment where if I leave it to sit overnight, it will need cranking up to 10 times before it eventually fires.

I was thinking massive boost leak perhaps, maybe in the fuel vac lines, but then I saw somewhere else in a thread something about a one way valve that stops fuel flowing away from the engine after the engine is turned off.

It definitely feels like there is no fuel getting to the engine, and then as I continue to crank it slowly but surely gets there and then eventually has enough fuel to fire. I've left the car sat now as I don't want to cold crank it. I recently had the fuel pump changed, so wonder if something went wrong during the change.

Anyone know about this one-way valve?

 

[<tuffty/>]

As far as I am aware thee is a one way valve built into the pump... The effect you describe often happens more when the tank is less than half full...

There are no other check valves in the fuel system that I am aware of

<tuffty/>

 

[Squirrelofdoom]

Hi tuffty,

Yeah, had this problem with the car when on low fuel and got worse and worse until the pump finally died. Got the pump replaced and all was good until recently where it's happening again.

Anyone had this before and replaced JUST the valve rather than the entire pump?

 

[Alex C]

new OEM pump installed or old 2nd hand one?

 

[Squirrelofdoom]

Was one of these: http://www.ebay.co.uk/itm/281147205846?_trksid=p2059210.m2749.l2649&ssPageName=STRK:MEBIDX:IT

AUDI A3 (8L1) Fuel Pump - VDO 993-745-117Z

 

[Alex C]

does the A3 Quattro (180bhp) use the same pump as the S3? - I honestly don't know the answer to that one

 

[mattyboy199]

I just replaced my pump & amazed how much difference it has made. It kind of brought the car back to life

 

[Squirrelofdoom]

It helped for me too - but now obviously something is broked again

 

[Squirrelofdoom]

any ideas guys? Would be good to have an idea of what I'm actually looking for before taking anything apart

 

[Alex C]

new fuel filter?

 

[Squirrelofdoom]

Had one fitted at the same time as the pump was

 

[marlow77]

I have similar staerting problem with mine for months now but I don't leave it cranking for ages, simple turn it over for 1 second, switch off and turn over again and it starts. but it won't start on the first turn of ignition

 

[Jenno007]

I have recently just got this problem, where it takes a bit of cranking to get going. I'm going to replace the fuel filter this weekend and see if that helps. Otherwise I will just keep the tank more than half full as much as possible.

 

[Squirrelofdoom]

Hi guys, that's exactly how mine started - taking a little more effort to start, but nothing weird. And then suddenly the fuel pump went entirely (not uncommon on these cards) and so I replaced it and the fuel filter at the same time. Was all fine for a few months and has not deteriorated again.

By the way, no fault codes on the car

 

[Alex C]

so I replaced it and the fuel filter at the same time. Was all fine for a few months and has not deteriorated again.

now?

 

[Squirrelofdoom]

lol, yes NOW...typo fail