Volvo Repair: 86 volvo 240 dl auto transmission, volvo 240 dl, vacuum leaks

Question
3 weeks ago after fueling up at gas station I noticed the car started idling a lot rougher and losing power when accelerating.  A couple days went by and the rough idle stayed the same but the hesitation and the loss of power got worse.  I took it to a friends mechanic who gave me a free diagnosis and he checked compression and everything else that has to do with the engine.  He found that the compression was excellent and the engine seemed fine so he thought that it was bad gas or a dirty fuel system.  He told me to put seafoam carbon cleaner in the system and thought that it would do the trick.  After that I took the car from san diego to seattle with the same problems but the car still made it the 2000 miles that I traveled.  In the last week the car has hesitated a lot in between gears and makes an almost jerky motion as it catches up to the acceleration but runs good at high speeds and has power at high speeds. I have checked all fluids and they are good but I don't know if this problem has something to do with the fuel injection or system or the transmission? Obviously, I don't know much about car but if you have any suggestions I would appreciate it very much?  Thanks  

Answer
Hi Ben,

    There are many reasons for why your car runs poorly at low speed...spark plugs ..wires.. dist.cap.. coil..air/vacuum leaks...fuel injectors..failed electrical connections...the list goes on.
  You should find a competent mechanic who understands
  Bosch fuel and electrical systems.

  good luck,

          Bilbo