Warm hot start won't start only stating when cold then cuts out when warm

enzo

Member
Ok Iv have this issue that's kept my a2 atl
off the road for over 6 weeks now


Filled up with fuel when it was really low

Pulled out of the forecourt it got 200 yards before dying

She starts when cold on the button
But once warm she will eventually cut out
Or if I switch off after 4 mins use she won't start again


Now Iv changed
camshaft sensor,
crankshaft sensor,
coolant temp sensor
and the fuel filter

And It still does it

So looked into the 4pot version of these engines
One interesting post points to the lift pump failing in the fuel tank.

This seems the most plausible explanation but as I'm no expert I need clarification on a few things

Is the atl a pd unit?
Should the lift pump in the tank make any type of priming noise when I turn the key ??

Is the lift pump accessible on an a2?

Are they expensive/ready lily available ?
Any help would be apreceated so much
 
Ok so I got to the lift pump I think I'm not sure what I'm looking at

Was expecting fuel to sqirt out of this hole when I turned the key but nothing

Hooked up the other one to a container and fuel did come back through after she started from cold


Just uloading photos the now
 
Sorry forgot to say Iv done vcds scans multiple times in the past six weeks

There are now now codes on the system
 
ok after searching the forums it seams there might not be a lift pump in there after all but i cant go on hearsay..
i spoke to my mechanic mate and he seams to thing there is a low pressure pump in there which feeds the high pressure tandem pump as its a pd?????

does this sound right to anyone.

might look like im back to square one but here are the photos to go with the previous post

liftpump.jpg


liftpump2.jpg
 
a2-1634.png


well the fuel collector does look like a lift pump after all with a sender unit etc
 
theres no pump in the fuel tanks on TDI's just the vacume pump on the end of the cylinder head pumps all the fuel

As you say the problem started after low fuel and a fill up , have you ruled out contaminated fuel ?

id suggest something like my diesel purge treatment process to see where you stand...

firstly go get some fresh diesel in a ready can and a few foot of fuel hose from your local motorist store
then as you look into the engine bay at the front of the engine youl see 2 chrome looking stainless fuel pipes
if you look to the cam belt side of the cylinder head youl see where these 2 pipes swap to rubber pipes
disconect both of these and connect your new pipe on both of these and chop the pipe middle ish
then stick both ends into your ready can so youve got fresh fuel ready to be sucked into the engine

start her up and let her run and warm up a bit and start stop as you need to see if engine faults resolved

if the fault is resolved its either going to be bad fuel or a posible air leak , as in one of the fuel line conections from the tank to the fuel filter or the fuel filter assembly, fuel filter contaminated with water possibly..

if its not resolved id be looking at the vacume , tandem pump being at fault on the end of the cylinder head

Good luck and i hope this helps
 
Last edited:
if someone witha tdi atl could just confirm if there is any type of priming noise at the tank when the switch the ignition on then i think i might have this nailed.. but then again maybe not..
 
well thats that scupoured then :/
thanks for confirming jigsaw..
 
Last edited:
theres no pump in the fuel tanks on TDI's just the vacume pump on the end of the cylinder head pumps all the fuel

As you say the problem started after low fuel and a fill up , have you ruled out contaminated fuel ?

id suggest something like my diesel purge treatment process to see where you stand...

firstly go get some fresh diesel in a ready can and a few foot of fuel hose from your local motorist store
then as you look into the engine bay at the front of the engine youl see 2 chrome looking stainless fuel pipes
if you look to the cam belt side of the cylinder head youl see where these 2 pipes swap to rubber pipes
disconect both of these and connect your new pipe on both of these and chop the pipe middle ish
then stick both ends into your ready can so youve got fresh fuel ready to be sucked into the engine

start her up and let her run and warm up a bit and start stop as you need to see if engine faults resolved

if the fault is resolved its either going to be bad fuel or a posible air leak , as in one of the fuel line conections from the tank to the fuel filter or the fuel filter assembly, fuel filter contaminated with water possibly..

if its not resolved id be looking at the vacume , tandem pump being at fault on the end of the cylinder head

Good luck and i hope this helps


****ing awesome! sorry i replied and didnt see your edit!
thanks you so much for the info. jigsaw.. how can i repay you for the stress uv just relieved off my chest..
really dont want to let this a2 go and its been spinning me out weather too or not, iv learned a lot about the car mechanically in the time iv had it which is good though but still a stress never the less.. like trying to get the clip off the back of the coolant temp sensor was a ******* taking me 4oish mins lol

im gona do that diesel purge and see where i get with this.. it should give me the answers i need to sort this out and finally get it back on the road. was so close to buying a caddy2k but really want to keep this as my work van for obvious reasons of why we like them.

thanks again, il report my findings.
 
Back
Top