Hey fellas, Symptom#1: As the title says my 94 hijet has no power or pull when switching from 4th to 5th gear. It will actually slow down. I use to hit 110kph no problems now it struggles to do 80kph. Symptom #2: Taking off from a light or stop is slow slow slow if the AC is on. Gotta turn that sucker off for any acceleration. All of this is making me lean towards a vaccum advance problem, after some previous starting issues I have the carb dialed in to a nice 1200 idle and solved that whole issue. Any other thoughts? Whats the surefire way to test if the advance is working or is the culprit?