AGU BOOST PROBLEM!!

[ahidas]

Hy. I am new to the forum and I would really need some help guys. I have a MK4 with a AGU. I bought it not long ago. It had some work done to it in the past. It has a decat downpipe and cold air intake. It had a stage 1 map on it I believe as the previous owner said. I put a boost gauge in and realised it boost to between 18-20 psi depending on how quick I accelerate. But when I by the time I hit the 5000 rpm the boost is dropped to about 7-8 psi. I believe this is not normal for these engine. I have checked the diverter valve and changed it with a dump valve but no difference being made. I have checked the n75 with another and did the same. Changed the airflow meter with another one still no luck. I'm unsure if there is something been done while their remapped the car or there is a sensor playing up or a boost leak. I'm unsure which boost pipes to check for.


Thanks for the help !

[viperjsy]

check all the pipes coming off the turbo and all the vac pipes including the tip and throttle body my golf agu boosts to 0.6 bar when I accelerate hard and drops to -0.4bar when I am driving normaly . use a diverter valve with a Yellow  spring   -    15-23 PSI
all these pipes

depending on your setup for your inntercooler

[Wazzzer]

your boost will drop off the higher up the rev range you go