Low boost
 

(88 944 turbo non S). When I got it out of the garage this spring after sitting for the winter I noticed it did not have a get up and go it did before. I seen that the stock boost gauge was only going to 1.2 bar and not the normal 1.78. I thought it was the cycling valve under the intake that controls the waste gate. so I ordered a manual boost controller, 3.0 bar fuel pressure regulator, blow off valve, vacuum line kit and a boost gauge. I installed them this weekend and I still have the same issue. The stock gauge goes to 1.2 bar and the after market one goes to 4psi. Has any one seen this problem before? Could it be a defective waste gate? Any information would be greatly appreciated.

Have you checked your diverter valve? Pull the vacuum line off the top of it and try and suck through the nipple. If you can suck through with no resistance, then it is bad. If you can feel vacuum when sucking, then check for vacuum leaks elsewhere.

I replaced the deverter vavle and all the vacuum lines under the hood im thinking the wastegate might have blown but no sure

You can clamp the line to the wastegate with a visegrips and go out and drive it to check the boost from the turbo. Just get into the throttle, check to make sure the boost goes up past 12 or so, then get out of it quickly (the throttle). When you do this, there is zero wastegate control, so it will boost indefinitely, so be careful! If it still does not make boost, then there is an issue with the turbo.