1.8T Cupra, Jittery

[CJS-90]

I've been finding that low down in the revs, around 1500-3000rpm that if my foots in the same place on the accelerator, the car will surge forward then just die...

IE on my boost gauge the boost shoots up to about 0.2bar and the car pulls (considering i'm only feathering the throttle) and then drops back down to -4 vaccum pressure or whatever it is.

Not really sure why it does it!?

 

[ibizatom]

Checked all the vacuum and boost pipes?

 

[CJS-90]

Checked all the vacuum and boost pipes?

there's no lack of boost like, happily sits at 0.6 bar when i'm planting it and pulls all the way through (standard map), it's just when im on partial throttle that it does it

 

[CJRamze]

Coilpacks.
Hows the engine feel, Exceptionally juddery?

 

[Chino_UK]

Can also be a dodgy MAP sensor if boost is doing odd things.

 

[CJS-90]

Coilpacks.
Hows the engine feel, Exceptionally juddery?

Hmm not really

I've also noticed from a cold start, when it's high idling, rather than the revs being stationary on about 1300 or whatever, the needle seems to bounce around, say up 50rpm/down 50rpm

 

[wazza16]

i also experience this, when coming out of junction in first just light on throttle get a boost up then it goes bk to normal, look forward to seeing a cure!!

 

[CJS-90]

i also experience this, when coming out of junction in first just light on throttle get a boost up then it goes bk to normal, look forward to seeing a cure!!

Yeah I get that a lot too. It's not so much of a problem, just a little annoying that it's jerky and when you have passengers they sometimes think you're a jerky driver

 

[wazza16]

yeh it is a bit annoying eh, hope there is a cure for this!! keep me updated of any info pal!

 

[CJS-90]

yeh it is a bit annoying eh, hope there is a cure for this!! keep me updated of any info pal!

Will do

 

[twenny]

Alright Lads ,

N249 bypass cured my leon cupra and a freinds cupra R , they used to do the same at around 1800 rpm , try that see if it cures it ,

hope this helps , all the best

twenny

 

[wazza16]

ok doke will try anyway. let u know!

 

[CJS-90]

I'm not sure if mine's already done or not...seems to be lots of endless pipes though lol

 

[twenny]

Alright mate ,

looks like it has but badly , get them open pipes sealed , a bolt and zip tie at least mate .

cant think why theres a check valve there tho , mine ive literally teed into the FPR pipe ,then straight to DV , i did the same on cupra R too . then block off any open ends with a bolt and zip tie .

block your open tubes and go for a drive mate ,

hope this helps

twenny

 

[CJS-90]

Alright mate ,

looks like it has but badly , get them open pipes sealed , a bolt and zip tie at least mate .

cant think why theres a check valve there tho , mine ive literally teed into the FPR pipe ,then straight to DV , i did the same on cupra R too . then block off any open ends with a bolt and zip tie .

block your open tubes and go for a drive mate ,

hope this helps

twenny

There's another open one behind the vaccum box too. Will block them and see what's what

 

[twenny]

Yeah mate ,

You might find there not connected to anything which could be why there left open /unplugged ???

if thats the case at least you know there not causing the issue ,

twenny

 

[wazza16]

where is the one going to off the check valve?

 

[CJS-90]

Alright mate ,

looks like it has but badly , get them open pipes sealed , a bolt and zip tie at least mate .

cant think why theres a check valve there tho , mine ive literally teed into the FPR pipe ,then straight to DV , i did the same on cupra R too . then block off any open ends with a bolt and zip tie .

block your open tubes and go for a drive mate ,

hope this helps

twenny

Just spend 40minutes searching for various different pictures, and they all have open ended pipes so I dont think it's that?

 

[Hartosh1]

Mines does this aswell and i have done the n249 bypass along with sai removal. Could it be my maf on its way out? Really annoying as my car keeps going into safe mode aswell for no reason then will come out it after driving a bit then go back into it need to get VAG COM plugged in to see if theres any faults as my EML is always on due to decat

 

[twenny]

Alright mate ,

any left open pipes wont be connected to the engine ,

im more intrested in the reason behind the check valve being were it is ???? .

cant see it in daemorgans guide . Personly id take that valve out of the loop and see if its any better .

problem is with out been there seeing/driveing your car any attemp at diagnosing your issue is made ten times harder . so any advice you recive on a forum is always best guess based on the info youve provided mate
.

hope you get it sorted mate

twenny