Engine Performance problem
1994 Volvo 940 6 cyl Two Wheel Drive Automatic 209000 miles
We have a 1994 volvo 940 It revs about 90 percent of the time. The mechanic was sure it was the fuel control valve. It still revs, it also is very hard to start first thing in the morning and all day long it will crank and crank and smell flooded. Eventually it will crank to a start. Someone has suggested that it is possibly an o2 sensor. What do you think?