1987 Volvo 740

Engine Performance problem
1987 Volvo 740 4 cyl Two Wheel Drive Automatic 300000 miles

A few weeks ago I got this volvo 740 GLE. The turbo is turned up to more than factory specs. I recently changed the oil in it and my mechanic recommended 20-50. I also changed the oil filter. Recently I also had the spark plugs cleaned and replaced. Also my thermostat housing is leaking, probably from a busted o-ring. Today it was very cold outside and the car wouldnt start, it would turn over and if I gave it some gas it would increase in revs with a really rough idle, so I decided to leave it alone until later today, any ideas?
February 17, 2009.

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