Not Boosting Properly?! Causes??

[Beaker™]

Car usually peaks at 1.5bar and holds at 1bar.

But today it will not peak past 1bar, its felt very sluggish for the past few days i was suspecting MAF. So tried unplugging it, but still peaks at 1bar, also borrowed someone elses MAF and still no difference.

What else would cause this? Changed a few vaccum hoses yesterday but all was fine after that. Started playing up today.

Quick reply would be appreciated as i got the bonnet open as we speak

 

[flashbsd]

n75? have you knocked the wiring plug out or anything or "disturbed it"

 

[Beaker™]

n75? have you knocked the wiring plug out or anything or "disturbed it"

Where is the N75 valve?

 

[Beaker™]

Checked all the hoses/plugs i can see, everything seems ok??

 

[Martyn]

Any fault codes? Log block 115 and 118 if you can.

 

[CupraUK]

I'm with Flashbsd, I knocked the connector to my N75 when fitting my Forge DV and boost was very low. Pushed it on nice and tight and Mr Whistley came back.

Don't know where it is on the Beeza.

 

[Martyn]

Usually you can only boost to 5psi if the N75 isnt connected/knackered.

 

[Beaker™]

Right been up Ollys house and swapped my N75 with his, still not boosting properly. Have no access to VAG COM so cant log it REALLY doing my head in now!

Did hit 1.5bar twice on the way home in 2nd gear but that was it.

Been over all vac pipes and all other hoses and plugs that i could see. Also re aligned throttle body and unplugged ECU. Still no joy.

 

[Beaker™]

Any fault codes? Log block 115 and 118 if you can.

Just out of interest what would that be checking?

 

[Martyn]

It'd tell you whether the ECU is actually requesting and delivering the correct boost.

If your N75 duty is max'd but you're not building boost then you've got a big boost leak.

 

[Beaker™]

It'd tell you whether the ECU is actually requesting and delivering the correct boost.

If your N75 duty is max'd but you're not building boost then you've got a big boost leak.

Oh right, well like i say i just tried an N75 that i know is working and that didnt help. Also checked everywhere i can think of for any kind of leaks. I'm at a complete loss now. No idea what to do next.

 

[Martyn]

Find someone with vag-com and do what I suggested mate.

 

[Beaker™]

Find someone with vag-com and do what I suggested mate.

Will do, put up a post but i don't think there is anyone near me with VAG COM, i'm guessing the dealership will charge a fortune to plug it in?

 

[Martyn]

I dunno mate, my car doesnt go anywhere near my local dealer.....for a good reason

 

[Beaker™]

I dunno mate, my car doesnt go anywhere near my local dealer.....for a good reason

Yeah i try and do the same.

 

[CupraUK]

try the vagcom map to see if there is anyone near you

http://www.frappr.com/vagcomuser

 

[traumapat]

Car usually peaks at 1.5bar and holds at 1bar.

But today it will not peak past 1bar, its felt very sluggish for the past few days i was suspecting MAF. So tried unplugging it, but still peaks at 1bar, also borrowed someone elses MAF and still no difference.

What else would cause this? Changed a few vaccum hoses yesterday but all was fine after that. Started playing up today.

Quick reply would be appreciated as i got the bonnet open as we speak

i had similar probs and it was my dv sticking... just a thought

 

[Beaker™]

i had similar probs and it was my dv sticking... just a thought

Already tried that, cheers

 

[Beaker™]

try the vagcom map to see if there is anyone near you

http://www.frappr.com/vagcomuser

WOW!

 

[Beaker™]

Update, just took it out and it now its all over the place.....

1st gear peaks 1bar (slowly drops to 0.75bar)
2nd gear peaks 1bar (slowly drops to 0.75bar)
3rd gear peaks 1.5bar when it feels like it (holds at 1bar)
4th gear peaks 1.5bar when it feels like it (holds at 1bar)
5th gear peaks 1.5bar when it feels like it (holds at 1bar)

Before i started having problems it would easily peak at 1.5bar in all gears and hold at 1bar. Not a good day today