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Nevyn · 02-21-2009, 08:17 PM

Search around for DFCO - that's the common abbreviation for "Deceleration Fuel Cut-Off." My 93 Lumina does it. Drop it from 4 to 3 when warm and headed down hill, and you can feel the car slow down more than just the gear change. It's as if someone grabs the rear bumper and is holding on the car. My MPGuino also shows it - the instantaneous gallons per hour drops to zero. The engine is still turning, but it sounds funny - has a weird "woosh" sound to it. It keeps engine vacuum, so I never lose power brakes, but there is definitely no fuel. When I kick it back to 4, the tach drops like a stone to about 200 and then you can hear/feel the "vroom" as it turns fuel back on.

02-21-2009, 08:17 PM	#3 (permalink)
Nevyn Master EcoModder Join Date: Nov 2008 Location: 18603, USA Posts: 759 The Crimson Crawler - '04 Hyundai Elantra GLS 90 day: 36.71 mpg (US) Thanks: 221 Thanked 60 Times in 45 Posts	Search around for DFCO - that's the common abbreviation for "Deceleration Fuel Cut-Off." My 93 Lumina does it. Drop it from 4 to 3 when warm and headed down hill, and you can feel the car slow down more than just the gear change. It's as if someone grabs the rear bumper and is holding on the car. My MPGuino also shows it - the instantaneous gallons per hour drops to zero. The engine is still turning, but it sounds funny - has a weird "woosh" sound to it. It keeps engine vacuum, so I never lose power brakes, but there is definitely no fuel. When I kick it back to 4, the tach drops like a stone to about 200 and then you can hear/feel the "vroom" as it turns fuel back on.