loss of turbo pressure

[axel l]

Hi.

recently my ibiza mk4 1.8t fr started to cut of my turbo pressure at around 4500 rpm. the boost falls to 0 bar. if i shift to a higher gear it boost again, but only to 4500 rpm

it is not doing it all the time, somtimes it runes fine, but with a slightly lower pressure than normal.

i have tried to change the 3-way valve, but without luck

anyone who has an idea?

thank you.

 

[st10587]

could be dropping into limp mode. maybe worth getting a vagcom on it and seeing if there is any faults

 

[axel l]

i have thought of that to, but there must be a reason why it does that. I have talk with a lot of tuning companies, and they all say that they have to drive while they have a vag com on it.

i just wanted to hear i any off you have tried something like it or maybe had an idea to what i could be?

 

[GlanzaV]

I had something similar - but not exactly what you're describing on my mk3.

About 4500rpm in 4th gear my boost would cut from 15psi to 5psi (max) but I would need to turn off the engine before the safety cut would reset (not just change up a gear as you say) I would also get the 5psi all the way through the rev range. This was due to the Turbo intake pipe apparently collapsing and a forge TIP would have solved the problem.

I don't know why yours is rpm related though, and why you get boost in dif gears, but only up to that rpm?

Regarding VagComm - You can read any error codes that might have popped up without having the car driving, but to replicate the error and log it then you'll need to drive the car.

Do you have any other modifications?

 

[axel l]

it is very strange, because my car is still accelerating after 4500rpm, but without any turbo pressure and it is of couse very slow :/

Glanza V : it is not exactly like your problem :/ sometimes it is about 4500 rpm and sometimes it is about 5500 rpm, and other times it runs perfectly?

modifications:

chippet
turbosmart Blow Off for e-gas
removed cat
kn air filter replacement

 

[perikolos]

hy there, may be with the new chip... maybe it isn`t ok? the turbosmart is the dual port or the blow off one?

 

[axel l]

perikolos: i have thinked about that to, but it has driven with it for about a year now? it is a single port blow off, and it has driven fine with it for quite some time now, but i have tried with the original valve to, with out luck :/

i should start my car for about 15 minutes ago, it started fine, but right after it started it went out again, it dit i several times. then i took the minus wire of and waitet some time, and then it startet fine with out turning it self off? but then the airbag indicator popped up :S

something must be wrong with the software or what?

 

[perikolos]

that isn`t normal... abiut the blow off valve... this engine doesn`t work well with this valve... so the problems you have might be related to that, I have a friend that has a golf diesel and had a similar problem and it was the map sensor... on the other hand a client of mine had a similar problem with his s3 and for him was the fuel pump that didn`t work fine (not enough fuel on high revs and top gears -> car went in limp mode but didn`t need to be restarted just a shift up or down...)

 

[axel l]

Perikolos: maybe you are right. the fuel pump could be the problem. do you now when it has to be changed? my car has gone about 83.000 km and i made the 71.000 service, but i think i forgot to change the fuel pump. do you know when is had to be changed?

 

[perikolos]

sorry I realy have no clue! but if u find out let me know to please....

 

[axel l]

i have just bought a fuel filter. i am going to change that later today. if it works, i will let you now

 

[axel l]

i hvae just changed my fuel filter, but it diden`t help :/

any other suggestions please?

 

[perikolos]

check the fuel pump. it may be working ok on low revs(low presure) but on high revs might not work ok....

 

[axel l]

ok, that could be an idea. is it possible to check if its okay, ore do i have to replace it?

 

[perikolos]

you could check it with vag com in a log, but you would need a log from a similar car that is ok... to compare the results

 

[axel l]

i have just bought a bluetooth odb ll diagnoser for my computer. i hope it can detect the problem

 

[CupraRobX]

Any chance someone could post a pic or point me in the right direction of the N75? I've had my head under the bonnet for about 10 minutes and have no idea where it is! Ive got the PD130 engine.

 

[fr_craig]

does it sound like it missing or does it just lose pressure

 

[axel l]

evoke1xt: i am not sure what a n75 is? but if you mean the 3-way valve, then it is located on the intake tube, right after your blow off valve. it got a electric wire to it and 2 small tubes. hope it will help, and sorry my bad english

fr_craig: i dont think i understand your question?