I'm new to Volvo so please excuse the stupid questions. I'm working on an 83 240 turbo wagon for a friend. The original complaint is: The engine has a severe cutout upon medium to heavy throttle. very slow accelleration works ok. After some study I thought that perhaps the turbo wastegate was malfunctioning and causing the fuel pump to be shut down. Watching the wastegate with a mirror while giving throttle showed no movement. I moved the valve by hand after a little struggle (it appeared to be stuck). Tested the valve by applying air pressure (unregulated) and valve did move. Test drove the car and the problem seemed to go away (at least at medium throttle). I fear this fix is only coincidental because of the way the dash guage reads. The guage is not marked for pressure or vaccum, so I'm making some assumptions that will probable prove wrong. Hence my imeadiate questions are: Does the needle going left indicate vaccum and going right indicate pressure? If so, Why would I only show vaccum (in range of 10-20 on the guage) and no pressure ( the needle never goes to the right) and how would this affect my original complaint (the fuel cut off)? Am I chasing down the wrong street? The original problem appears to mimmic an earlier problem when the hose fell off the intercooler and lost vaccum to the plate in the fuel distributor.I would appreciate any help or advice you folks can give me.