Im hitting peak boost but then the car wont hold it and then itll tail off to 7psi...

[mitch2028]

Hi all im having a problem with the cupra....my car will spike at 21-22psi and hold a healthy 18psi. Ive swapped all my hose clamps on the car for even load clamps with worm gears on them....i doubt its a boost leak but i havent had chance to check yet. The symptoms are when im giving the car full boost she'll get to the 21-22psi and not want to hold the 18psi and just tail off to 7psi and stop there (limp mode?)

Ive had a read and it does sound like a boost leak sort of but like i say i doubt it with these new clamps...fuel filter also came to mind...maybe bad fuel delivery at high boost? i got a fuel filter when i brought the car so maybe its due a change?

any help is appreciated

 

[PhilW]

What mods do you have?

Sounds like positive deviation in the boost, i.e your making too much vs what the map is requesting, thats what sending you into limp mode.

Any fault codes?

 

[SEATCOOBER]

get it on vag com!!!

 

[mitch2028]

cheers for the advice...ive just ordered a vagcom lead and got vagcom. The car has alot of mods...FMIC, forge dv, jabba custom map, 4 bar fpr, induction kit, n249 bypass, vr6 clutch, g60 flywheel etc etc. ill let you know when ive put the computer on it..its only doing it on and off now was sound early but its done it when i just took it out

 

[Reuvers]

As said by Myki in a different thread today, might be a coilpack on the way out, meaning it doesn't fire all the time...
However that might not show up on vagcom

 

[ibizacupra]

when you say tail off... is this at the higher revs? as if so, thats the K03 turbo for you being basically flat out.

 

[mitch2028]

my cars has a k03s forgot to post that....i thought maybe a coilpack too, sort of sounds like a mis-fire when it does it. will find out tommorow when the vagcoms on it

 

[ibizacupra]

coilpack usually a definate misfire.. plugs ok? when were they last changed?

 

[mitch2028]

I honestly couldnt say i will ask the old owner later on...the cars also got a 3'' downpipe and racecat. Any recommendations on plugs? Im local to a halfords so will what they recommend for the cupra be ok or with it being non standard does it need different plugs?