930 boost problem
 

I have an 87 930 with 80k and it is not boosting all the way i replaced pop off valve gaskets, plug wires, intercooler gaskets waste gate has new diaphram booty, and checked compression and leak down are ok. after this it ran good but seems to be down on boost my oe gauge crapped out so i replaced it with a vdo boost guage and it only reads 10 psi and it should be about 15 with 1 bar boost spring.

relkeb,
How much play in your compressor shaft?

John B.

993 TT 6.0

Not sure havent thought to check it i will pull the pipe off and check it though thanks.

Check with tried-and-true pneumatic boost gauge first. Check hoses going to wastegate for cracks. Check turbo for damage, check if you realy got 1-bar boost spring, check wastegate-valve for damage.

Unless the wastegate is faulty I would also suspect the turbo.

At 130K miles with exhaust system cracks and partially blown intercooler o-rings my system could still easily hit one bar with a one bar spring.

thanks i will defenitly check the turbo thats probably what it is ive already replaced the hoses and the boost spring is brand new from performance prod.