Leon cupra slightly rough idle?

[mista_khan]

Hi

i dont know if its normal but i have noticed it, after engine has warmed up on my cupra , it idles slightly rough between 780 - 830 revs approx?
like the needle keeps boucning between the above revs, if that makes sense?

is that normal?

 

[Mr OCD]

Sounds like you have a vac leak ... needle should be steady.

Mind you it could also be the CTS playing around... what temp does gauge show when warmed up - does it move at all?

 

[mista_khan]

Temp is bang on doesnt move from
The centre ?

 

[Teasy]

mine did that but OK since I had a throttle alignment done (touch wood)

 

[mista_khan]

Im gonna give the throttle body a clean with wynns as well, how much does throttle alignment cost ?

 

[Mr OCD]

Im gonna give the throttle body a clean with wynns as well, how much does throttle alignment cost ?

I'm sure someone local to you will do it for free.

DO NOT clean the throttle body until you have someone who can reset it straight after as the car will run like crap without the reset.

 

[mista_khan]

I'm sure someone local to you will do it for free.

DO NOT clean the throttle body until you have someone who can reset it straight after as the car will run like crap without the reset.

Oh **** yes i need a vagcom right ? Can i buy one off ebay ? Not sure if i know anyone local

 

[Shmoo]

it can be done without vagcom. I removed my throttle bodie and left it plugged in. my mate pushed the accelerator so I could access and clean everywhere refitted and works perfect.

 

[mista_khan]

it can be done without vagcom. I removed my throttle bodie and left it plugged in. my mate pushed the accelerator so I could access and clean everywhere refitted and works perfect.

i wont be taking it out and yes thats the way i done it on my polo, so can i do it like that on the cupra and not need to reset it?

 

[Shmoo]

yes it worked fine on mine

 

[Mannybee]

Yeah keep it plugged in and clean it. I reckon that could be your problem or maybe a split pipe

 

[mista_khan]

so lets quickly confirm what im gonna do is the right thing lol,

leave engine on in neutral
take off jubilee clip and remove pipe
make freind rev engine so clip opens and cloese
spray wynns carb cleaner until what comes out isnt black or dirty (without touching butterfly clip)
re join pipe and leave engine on for a few mins

correct?

 

[Shmoo]

no don't do it with engine running. do everything you have said above but just have the ignition on instead of the engine running and the flap will still open when pedal is depressed.

 

[Mannybee]

so lets quickly confirm what im gonna do is the right thing lol,

leave engine on in neutral
take off jubilee clip and remove pipe
make freind rev engine so clip opens and cloese
spray wynns carb cleaner until what comes out isnt black or dirty (without touching butterfly clip)
re join pipe and leave engine on for a few mins

correct?

Wrong

Just ignition on dude

 

[mista_khan]

lol see i knew id ask , thanks so ill leave it on ignition clean it and then start after re fitting pipe.

ill do it tmo

 

[mista_khan]

Ive cleaned it now, car started up rough but after 2 mins settled. Bad news is needle vibration hasnt stopped ? What would be my next best bet ?

 

[mista_khan]

so the revs are still jumping between 790ish and 820, so theres a slight issue somewhere, would anyone else know of this issue on the forum?

 

[RDS1972]

My bet would a small air leak as already mentioned. Not necessarily easy to find unfortunately. How does it run when warm?

 

[lmiller]

My cupra R is lumpy too on idle when warmed up. Bit annoying.

 

[Mannybee]

try to get it scanned and take it from there .