Limp Mode??

Hello,
First of let me star off by saying that I have little knowledge about the TDi's I got my first (2003 Jetta Wagon GLS with 95k) in August 2010. I did a few things to it I got a Kerma Tune, 1019 Injectors, STG.2 Endurance Clutch.

My Problem:
I notice this when my fiance drives but if the car is driven in the wrong gear (lugged at low rpms) for a little while it will cut power to the the turbo making the top boost 5psi according to my McNally Guage.

This Guage will also spike to about 21-23 psi for maybe a sec, when "getting on it" and then hold steady at 18psi.

Why is it going into this limp mode? and should my vnt15 be spiking so 23max psi?

Cheers

Drive it like you stole it aka "Italian Tune Up" and see if that helps! Seriously .. these engines like to be driven kinda hard!

You need to get a VCDS scan of your car. Look at the Vag Com tab on the top of these pages. You should contact a guru who will probably do the scan for free or a beer. A short trip to Jeff in Red Lion, PA will get you fixed up also. A scan is what you need to start fixing your car.

I have vcds

Well that is good please post if there are any codes. If not then we have to look deeper.

There have been no codes for a while

maybe something restricting the intake? i had a stock IC on my car that was plugged with oil it wouldnt boost past 15psi and kept going into limp mode until i changed the IC

See that is the thing it will boost past 15psi in fact will correctly hold and 18 and spike 21-23 psi

With original VNT-15s getting older and dirtier, boost control issues are becoming more common. It probably shouldn't spike more than 21 PSI and a spike shouldn't last more than a second. Max. 18.0 PSI sustained boost is fine.

See if you can replicate the problem (lugging the engine at low RPM) while logging measuring block 011 (refer to the logging guide here: http://www.malonetuning.com/logs). Once it hits limp mode, scan for fault codes with VCDS.

My VNT-15 has around 30k on it the dealer replaced it(under warrenty) I will get a log today or tomorrow..

The car has plenty of power but as soon as its lugged for a while the boost psi will max out at 5psi.. or at least thats what my McNally was telling me I had alot of problems with the guage so I sent it back to them but I believe it was working correctly at one point..

The obvious solution is to not let your fiance drive the car...

Yes that would be the easy solution, but it has happened to me before and It shouldnt