1994 K2500 Suburban 6.5 turbo.
I installed a vacuum test guage and when I drive even with a light foot the vacuum at the wastegate actuator on the turbo drops down to 0 when I approach 2K rpm driving up slight hills. Sometimes it comes right back when I let off the accelerator and sometimes it takes 5 to 10 seconds. Vacuum at the pumps stays at 25HG all the time. I also just installed a new wastegate control solenoid and all wires look great. I can not seem to figure out what else the problem could be. Other than that it runs great.