N249 Valve instead of N75????

[joshpmc]

Hi,
I recently purchased an ibiza cupra R from a fellow forum member. The car drives fine but will often drop off boost and go into limp mode.
I have looked for boost leaks, changed the temp sensor and disconnected the MAF and it still does it so this led me to believe the N75 may be the issue.
I purchased a new N75 valve from Seat (part no. 06A 906 283 E) and when i went to fit it it looked completley different to the one installed which is part no. 078 906 283 A which i am led to believe is an N249 valve.
Now my question is why would my car have an N249 valve where it should have an N75 valve???
Or is this an N75 valve? I am totally confused. I was told by the previous owner he had done an N249 bypass.
Please can someone help me. Ive not had the car long and it runs fine apart from this issue!!!
Cheers Josh

 

[truCido]

They are similar looking but are different and in a different location. N249 is different to the N75 and you cant have one in place of the other, when you do an N249 the two valves are usually left plugged in and sit on top of the engine

This is your n75

 

[joshpmc]

The N75 ive bought looks like that but the one thats on Looks different! And it has the part no. off an N249 thats whats confusing me. I think im gonna have to look into the N249 Bypass and make sure he's done it right! And then install the N75 valve.

 

[joshpmc]

Right im tryna get my head around this now. Apparently my N249 and N112 valves have been removed and i have a Type J N75 valve, this doesnt add up with the part number on it though. I am thinking i should put my N249 valve and N112 valves back in place and plumb me N75 valve back in. I have also noticed that for some reason my N75 is plumbed into my 007p is this correct?
I was under the impression that the N75 Should be plumbed into the TIP, Actuator and the large pipe that comes over the top (dont know what this is called) and the N249 Valve is what would be plumbed into the dump valve if it was there but as its not it should be plumbed to the Y piece on the Bypass which also goes to the regulator?
Sorry if this is long winded or doesnt make sense but i need to get to the bottom of it!!
Cheers Josh

 

[truCido]

Can you take a picture of it all?

 

[joshpmc]

Ill take a pic tonight and post it up. I was looking at your N249 Bypass how to guide Tru Cido i might have a go at redoing it all on mine this weekend if you cant find a solution from the pics.
I will put them up on here about 8 ish.
Cheers Josh

 

[joshpmc]

It all looks ok to me after looking tonight but maybe someone can shed some light on it for me?

I appologise for the state of my engine bay it is an absolute state i know!!

 

[tom w]

WTF is that! That's no normal n75 ! And your bypass is incomplete as the n112 is still plumbed in

 

[truCido]

Actually the n249 bypass looks correct.....

I dont have a clue what that massive grey thing is but it looks like its where the N75 is supposed to be so I'd replace it with a proper one

 

[joshpmc]

Ive bout an N75 F valve but when i put it on it only boosts to 6/7 psi and whats wrong with the N112 valve bypass. I dont know much about it the car was like this when i bought it.
Does the big grey valve not look like an N249Valve to you?
Cheers Josh

 

[truCido]

The big grey valve is the N75...replace the grey valve with the n75F you bought

 

[joshpmc]

I replaced that with my new N75 valve at weekend and the car wouldnt boost. I may have had it plumbed in wrong, i will try again in my dinner.
Any body know anything about the N112 valve ive had a read through some of the threads about it and it mentions resistors have to be put in its place. Will it make a massive difference if i remove it?

 

[stuibaby]

My N112 Valve still remains in place to trick the car, i dont know what resistor is required - or whether it makes it nay better than having it sat there just plugged in electronically.

Stui

 

[truCido]

Replacing the N112 with a resistor does nothing apart from tidy up your engine bay

 

[joshpmc]

Cheers Guys i will put the N75F on in my dinner and have a look at the N112 tonigh or at weekend.

 

[tom w]

The long spout of the n75 into the tip the left hand spout into the actuator and the top spout into the charge pipe , I got rid of the n112 and ran a separate vac line to the dv from the manifold , also ran a line from the manifold to the fuel regulator to get rid of joins

 

[joshpmc]

Put the new N75F on and the car only boosts to 7 psi yet with the old valve on it boosts to 20psi. Has anybody got any ideas as to what might be causing this?
Cheers Josh

 

[tom w]

Is it mapped? As it could be over boost

 

[cupra-gaz]

thats one strange set up, why is the fuel regulator plumbed in to the vac line to the bypass like that? this is the guide i followed and see if you can make sense of anything from it
http://www.vagowners.co.uk/forums/showthread.php?303-Ibiza-MK3-N249-Bypass&p=101676#post101676