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Discussion Starter · #1 ·
just driving home from work and put my foot down and there was no power, it was fine this morning. Any one got any ideas what this may be, i have recently fitted a n75j valve could this be the cause or is it more likeley to be a turbo boost pie leaking?? any ideas of u lads would be appreciated
 

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Check the vacuum hose to the DV.  Mine did exactly the same and at first everything looked OK.  However on closer inspection I found that the vacuum hose had gone hard and brittle and had lots of tiny cracks.  A new one sorted everything out.
 

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I may be wrong, but I don't think AGU's do limp mode do they?  There's no MAP sensor so the ECU doesn't know what boost is being produced - or is that an invalid assumption on my part?
 

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Not sure actually!? You might be on to something. But I see this happen an awful lot when people mess with the N75's. So thats why I pointed a finger at that 1st..
 

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Discussion Starter · #6 ·
im not sure about limp mode?? ill try the old n75 valve back on later and c if that sorts it, i have heard of people disconetting the batt to reset the ecu  when the agus go into that limp mode so i could try that too, would the vag fault finder and the dealers pick the fault up?
 

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It's not limp mode it's a loose pipe. 5psi is the pressure the wastegate operates at if it isn't overrided by the N75 which leaks off boost to control it.
 

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Not sure actually!? You might be on to something. But I see this happen an awful lot when people mess with the N75's. So thats why I pointed a finger at that 1st..
...and I agree with you Paul that it's a reasonable place to start given that he's just messed with his n75. I only mentioned the DV as an alternative since mine turned out to the hose when I had my n75 down as the main suspect too. [:D]
 

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which pipes would you recomend checking first??
The ones you messed with when swapping the N75, also stick the standard N75 back on. Have you got jubilee clips on all the hoses attached to the N75?
 

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Discussion Starter · #12 ·
 clips on the valve are jubilee, im going to go try a few things now, ill let you all know how i get on, cheers for all the help thow you lads are really clued up when it comes to things like this
 

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Discussion Starter · #14 ·
the problem was the n75j valve, when i went back to the car after talkin to you lads it was workin fine again so i tested performance n75 j against the stock c valve and the j deffo was boosting better and was quicker so i thought id leave it on, but took it for a spin make sure it was working ok and the same thing happened again, 5psi max boost, so this proves that agu engines do have a limp mode to protect the engine from over boosting, wish i could overcome this problem so i could run higher boost
 

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I have the exact same problem,and at the mo have gone back to the standard n75.If you manage to sort out the problem i would like to know.
I found that when i fitted the n75j and went for a spin it was fine but when i went out later -no boost.I checked all the hoses and couldnt find anything but as soon as i changed back to standard n75 car was fine so i have assumed that i have a faulty j valve.
 

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Glad you managed to track it down but I still have my doubts about AGU limp mode.  I've been running an n75j for quite some time now and have often seen boost spikes of 18 psi (assuming my gauge is accurate) without limp apart from the vacuum hose incident that I mentioned. 
 

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im pretty sure AGU's Dont have limp mode, they have No MAP sensor to measure boost. im on stage 1 and spike 22psi on my newsouth gauge and have Never gone into limp mode.

could just be that ur J valve is faulty?

ive tried all the different N75 valves and found std one best may not spike as much, but does hold boost all the way through better than the others.
 
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