QuestionI have a Volvo 1991 DL. For over a year it has been getting low gas mileage. The first diagnoses was computer problems - the computer thought the engine was always running cold and sending too rich a fuel mixture. After trying 2-3 junk yard computers, with no help, I went to a different mechanic, who said there were two engine temperature sensors, and that the first mechanic had replace only one. He replace the second, said the computer was good, but still had a lot of difficulty getting the computer to clear. After working on it for a month, I got it back. The gas mileage never improved, and at the present, it won't start. Plugs are clean, spark seems good.
I have replace the oxygen sensor, both engine temperature plugs, the spark plugs, the timing chain, cleaned the flame trap and the water pump.
I would appreciate any ideas.
AnswerMike, these werent very good on gas even when they were new. The fuel pressure regulator may have a leak. Can you hear the fuel pump run when you crank the car? Do you have spark? Are the injectors firing up? I would moan to this guy and take it back. He must have done something else to it. Without doing a few tests, its hard to tell whats going on. Roger
