1991 Cadillac Fleetwood Gas Mileage

1991 CADILLAC FLEETWOOD
74,000 MILES • V8 • FWD • AUTOMATIC
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BRETT 7800
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I have a 91 Cadillac Fleetwood that has a good engine and transmission, but when I am driving it in the city I am getting very poor gas milage. On averageit is about 7 MPG. I will notice that when I am driving at about 45 MPH and the engine starts to shift into overdrive, the engine will start to bog down as if there is a poor air/gas mixture going on.
I also notice that when I am on the highway the MPG is a lot better but it is still not reaching its expected MPG. There is no problem when it is parked and running, but you can tell it is running rich. I have also had to go with an 87 octaine gas to reduce the engine from boging down.
Thanks
Dec 15, 2009 at 2:21 PM
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FACTORYJACK
  • ASE Certified Mechanic
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  • ASE Certified Mechanic
Has there been any tune-up work on the vehicle? I would also check injector resistance, should be around 13-15 ohms warm.
Dec 15, 2009 at 10:36 PM
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