HELP ANYBODY KNOW........Boost issues....... KO4

[joesgti]

RIGHT!!!!!!!!!!

As some of you will already know i have put a complete ed30 engine in my gti (when i say \\\'I\\\' i mean Monk, LOL)

It has REVO STAGE 2+ MAP and my mods are TBE, TWINTAKE, HPFP and all the other bolt on\\\'s inc S3 cooler.

But

The boost is spiking??! its on the boost then off, then on, then off, then off, its like im letting off the gas, then going back on, constantly when flooring it??

the car is requesting 2550 and is reaching 3000, im getting the logs sent by email today so il post them up and see if anybody has any idea, spoke to REVO on the phone and didnt seem very helpfull at all,  :WalkingSad:

Does anybody know what the N75 valve is and does? could this affect the car in the way i have decribed? anybody had any of these issues before?

Im hoping that some technically minded people will have an instant answer for me!!

[JPC]

Joe















That is all!

[Hurdy]

The N75 valve electronically controls the wastegate duty cycle, so it could be a faulty valve or even the wastegate actuator itself sticking and releasing. I doubt if it would be the setting of the actuator if it hasn't ever been moved from the factory setting on the threaded shaft.

[joesgti]

so you the next port of call is the valve?

whats involved in changing the wastegate?

[GTIjames]

what revo settings are you running joe ? and does this happen in any particular gears or all the time?

i use to get similar issues if i turned the timing up too much, boost spiked then dropped suddenly before spiking again, T5 works well for me and thats with vpower 

[Hurdy]

so you the next port of call is the valve?

whats involved in changing the wastegate?

Have you done any VCDS logs yet? I'd prefer to see logs before comitting to a diagnosis.

Does it fully spike each time or is it just a resonant spike that gets less as it goes through the rev range?

Now the engine is in it would be quite a big job as it is probably easier to remove the turbo than try to extract the wastegate from the turbo in situe. You can get to the wastegate by dropping off the downpipe, drivers side drive shaft, dropping off the drivers side engine mount and then removing the drivers side wheel arch, but it is a long job either way. I'll see if I can get hold of Steve Jr at Statllers and see if he agrees on what it could be before you start doing anything

[joesgti]

what revo settings are you running joe ? and does this happen in any particular gears or all the time?

i use to get similar issues if i turned the timing up too much, boost spiked then dropped suddenly before spiking again, T5 works well for me and thats with vpower 

i believe it was on the aggressive map, not sure on what the settings were,

then we turned it down to B7 T5 F5, im sure, and it still did it.

[joesgti]

so you the next port of call is the valve?

whats involved in changing the wastegate?

Have you done any VCDS logs yet? I\'d prefer to see logs before comitting to a diagnosis.

Does it fully spike each time or is it just a resonant spike that gets less as it goes through the rev range?

Now the engine is in it would be quite a big job as it is probably easier to remove the turbo than try to extract the wastegate from the turbo in situe. You can get to the wastegate by dropping off the downpipe, drivers side drive shaft, dropping off the drivers side engine mount and then removing the drivers side wheel arch, but it is a long job either way. I\'ll see if I can get hold of Steve Jr at Statllers and see if he agrees on what it could be before you start doing anything

I should be getting my logs through soon off ben at shark. so will post the as soon as i get them,

[Hurdy]

Joe, I've just come off the phone with Steve Jr at Statllers and he has two suggestions for the fault.

The first one is one he has come across in the past. The N75 valve has 3 pipes going to it and if any of them have a leak or a kink or aren't attached the wastegate will not operate correctly giving a boost spike followed by the engine dropping all power and timing to save itself and then the cycle repeats. This looks like a good place to look first.

edit....this wouldn't throw an error code either.

The second is if the wastegate itself has been adjusted and wound too far in. This wouldn't let the wastegate open correctly and the engine would again pull timing and power and repeat itself through the rev range.

Hope this helps Joe

[joesgti]

^^ cheers hurdy^^ thats great info, this is the first thing i will check when i get the car back! what you have decribed looks like what is happening and its possible monk has nocked a pipe off when putting the engine in.

Il get the logs up as soon as i get them, then if you could also send them to your chap steve that would be great, as he seems to know what he\'s talking about.

[tony_danza]

Good stuff there from Hurdy  I'm sure it's something simple.

Otherwise...

[neg]

I had similar problems on my LCR once, and this was down to the N75 being faulty.  The problem on the 2.0T is its a real pain in the a$$ to get at it - not much help I know.

On the other side, I didnt know you were doing this - good skills.

[QD MBE]

Good stuff there from Hurdy  I'm sure it's something simple.

Otherwise...

no need for that Mike................

Joes car is like one of those clown cars, bits fall off all the time...........

Wheel arch liners, spliters............

In fact there is more of Joe's car in Germany than in the UK



Ps hope you get it sorted shameless.

[monk]

Wastegate actuator--untouched.
Could be a pipe possibly moved when installing  motor and SJ has experience of seeing them regularly (but I doubt it).
Worth looking at tho to discount it....

[joesgti]

Wastegate actuator--untouched.
Could be a pipe possibly moved when installing  motor and SJ has experience of seeing them regularly (but I doubt it).
Worth looking at tho to discount it....

what do you mean? \'SJ has experience of seeing them regularly\'