Volvo Repair: 86 240 wagon, coolant temperature sensor, auto cruise

Question
86 240 wgn, 230k miles, auto/cruise
I just purchased this and it surges and sometimes stalls at a stop.  Otherwise it runs strong and feels tight.
Computer?, fuel injection or filter?
local mech. says time to replace the engine...
Please advise!
thanks S

Answer
Find a better mechanic.I would find someone familiar with Volvos the dealer would be best.it could be many things from air mass meter,coolant temperature sensor possibly a bad throttle switch.it will need to be looked at for a proper diagnosis.

 Rege