Leon tdi cupra 150 arl engine - slow and reluctant start when cold - NOW FIXED!!!

[MJ]

I've trawled through a few forums within the past week searching for a solution to the rather odd fault on my 2004 leon tdi cupra 150 with the arl lump fitted but i am unable to yield any information.

The fault started when i returned to the car after work on monday and it started for a split second, then cut out - as though the fuel had been cut off, then proceeded to turn over for about 5-10 seconds before startin. It was then fine! no power loss, no starting problems, smooth power delivery and smooth tick over???

I thought inicially that there was an air lock in the fuel system and it'd bled itself, i drove it home, then started it a few hours later and it was fine. I then went to my girlfriends and left it facing down hill and it started fine, I tried it at lunch time at work and there was no problem and i tried it several times throught the next 24 hours - UNTIL tody when it refused to start after work. Same scenario apart fromm there was no initial start up then cut-out. After 10 seconds of cranking it fired up and was fine?!?

No faults, starts fine afterwards and run ok.
The car had a cam fitted in april but has done 3000miles since without fault.
Eml light comes on and goes out as usual.
The car has 107k on the clock but has been locked after and was serviced fully when i bought it.

The anti shudder valve sticks occasionally but it sticks shut 3/4s of the way and allows air through - enough to start but limits power.

Any ideas or inputs would be very greatful!

 

[Hobbiniho]

if it is having problems startign from cold i would say that your glow plugs are not working as they should be

 

[MJ]

They have all been replaced and had the loom aswell, they'll normally throw up a fault at the touch of a hat when its the plugs, it feels more of an air/fuel starvation problem.
Like i mentioned above i have had problems with the anti shudder valve which did once stick completely shut and the car would'nt start - i was wondering if this has occured on anyone elses car?

Thanks for your reply mate.

 

[sssstew]

not saying it will solve the problem but youve identified an issue with the ASV so get that ASV changed, they dont cost too much.

 

[aaronbromley]

Could this be a fuel pump issue? I have heard of these causing the car to cut out.

 

[MJ]

The car isnt cutting out - it just randomly takes a while to start from cold then starts and runs fine. the power is still constant and it starts and runs fine everytime from there after.

With regards to the ASV i'm upgrading all the pipework at the mo and this is the last piece of the inlet system, i have an allards removal pipe but havent got round to fitting it yet.

I initially thought it was the 'pre pump' squirt of fuel into the cooler not working but i can hear the pump working and i parked it facing uphill (a very steep one at that) last night and i was ok this morning.

I'm gonna check the ASV is all the way open tonight then try it - i did try closing the ASV on another cupra tdi at work today and that was very much the same scenario, no start.

 

[Andrewcupra TDI]

i have similar problems , see diesel from drum post the latest pages

i suspect that mine is either pre fuel pump or the cap thingy on the fuel filter , it has now started to make a noise like pigeons or doves do

its only the 1st start of the day , doesnt matter whether its 7am or 7pm if it aint started that day would keep shutting down coughin and spluttering i have to hold the key on for longer for it to start

 

[MJ]

Mines just totally random, i've been parking it facing uphill and it still starts fine. Its only happened in the work carpark which is almost flat. I can hear the pre pump working but dont hear the initial 'splash' of fuel undernieth the car but i dont believe it should need to pump fuel through into the cooler as the system (at the moment) in full to the brim.

 

[MJ]

Same again tonight - no start, Turned over for a few seconds then went. I had some spare time when i got home so i've removed the rear seat and cover so i can make sure the pump is at least making a noise. I also removed the main fuel line to the engine and turned on the ignition - fuel came out almost instantly. I'll try another at work tomorrow to see what kind of pressure it comes out at and take the bugger out and inspect it (and reluctantly price one up).

 

[MJ]

i have similar problems , see diesel from drum post the latest pages

i suspect that mine is either pre fuel pump or the cap thingy on the fuel filter , it has now started to make a noise like pigeons or doves do

its only the 1st start of the day , doesnt matter whether its 7am or 7pm if it aint started that day would keep shutting down coughin and spluttering i have to hold the key on for longer for it to start

Mine was making the same noise this morning, i have sourced a 2nd hand unit (a bargain at £40 from middleton vw/audi breakers) and fitted it this afternoon - now only time will tell, however it does seem to work a little louder and makes a squirting noise when the fuel runs back to the tank.

 

[Andrewcupra TDI]

Mine was making the same noise this morning, i have sourced a 2nd hand unit (a bargain at £40 from middleton vw/audi breakers) and fitted it this afternoon - now only time will tell, however it does seem to work a little louder and makes a squirting noise when the fuel runs back to the tank.

let us know , reluctant to pay to take a chance too , new at trade was about was still alot

sources a 2nd hand one delivered for about 55-60 quid

am going to buy that valve thingy today (that sits ontop of the fuel filter , as it seems to make funny noises first start up of the day

keep us posted

cheers

 

[MJ]

let us know , reluctant to pay to take a chance too , new at trade was about was still alot

sources a 2nd hand one delivered for about 55-60 quid

am going to buy that valve thingy today (that sits ontop of the fuel filter , as it seems to make funny noises first start up of the day

keep us posted

cheers

Well mate i would'nt go and spend the money on a pump - no joy.
I'm gonna try (mainly because they are all peanuts):

A fuel filter return pipe t-piece
Fuel temp sensor
Supply pump relay
A one way valve for the fuel lines - because i suspect the fuel is running back to the tank for some reason

 

[Andrewcupra TDI]

Well mate i would'nt go and spend the money on a pump - no joy.
I'm gonna try (mainly because they are all peanuts):

A fuel filter return pipe t-piece - BOUGHT YESTERDAY UNDER £17 tradeneed to fit tonight
Fuel temp sensor under £20 already bought and fitted no joy
Supply pump relay
A one way valve for the fuel lines - because i suspect the fuel is running back to the tank for some reason

will let you know

 

[Andrewcupra TDI]

well mate

i fitted the valve thing on top of fuel filter , helped to start first time of the day , no pidgeon noises now , but still not starting when hot !!!

 

[MJ]

well mate

i fitted the valve thing on top of fuel filter , helped to start first time of the day , no pidgeon noises now , but still not starting when hot !!!

i'll fit the bits i have tonight including the one way valve and see how things go. With yours have you cleaned out the entire fuel system and sent an injector cleaner through?
With regards to using poor fuel - i fuelled up at asda and this is where the problems appear to have stemmed from, possibly too much detergent and not enough fuel!

 

[Andrewcupra TDI]

yes cleaned all the fuel lines , have been putting millers in , is there an injector cleaner that can be used on the pd engine safely

 

[MJ]

yes cleaned all the fuel lines , have been putting millers in , is there an injector cleaner that can be used on the pd engine safely

Ye we use forte diesel treatment at work - never caused any problems. Its basicly the same as millers but has no performance gains what so ever.

 

[muddyboots]

I'm gonna check the ASV is all the way open tonight then try it - i did try closing the ASV on another cupra tdi at work today and that was very much the same scenario, no start.

Have you checked your ASV yet ?

Like ssstew says, you've already had problems with it causing your car not to start, so would definitely be worth checking if you haven't.

 

[Andrewcupra TDI]

is it worth taking off and cleaning up , ir put a race pipe there ?

 

[muddyboots]

Easy (and free!) way to see if the ASV is the cause - make sure it's open (look at position of operating arm), then take the vac pipe off and temporarily block it so the ASV can't be operated and jam shut when the engine shuts down next time. Just be very careful removing the vac pipe from the ASV, I'm told it's very very easy to break the plastic pipe nipple off.