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Fuel Cut For Cold Starts?

5K views 10 replies 8 participants last post by  Shadow5501 
#1 ·
Hey everyone,

I'm wanting to pick everyone's brain and data center on this topic. So at a cars and coffee I attend, a fellow FoST owner (now drives an RS), had mentioned to me that if you perform the following sequence, it will cut the fuel from being injected and allow the oil to cycle through the engine before the car is actually running. He had mentioned that he did it on very cold days <10*f to get the oil flowing before the car is started. I was kind of puzzled at what he said, and he also mentioned that it's somewhat usual on DI cars. The RS does not do this.

Anyway, so I wanted to verify his statement when leaving. Sure enough the car cut the fuel and didn't start and kept turning over until I let off the gas pedal.

Sequence:

clutch in
Neutral
Floor the gas pedal and hold
Press the start button

While the gas pedal is held down as you press the start button, the car keeps turning over ( I guess cycling the oil through the block and building pressure?)...it is only after you let off the throttle the car injects fuel and the engine finally starts.

Can anyone/does anyone have any validation to this, or what it could be doing instead?

To my knowledge, it does seem to cut fuel as obviously the car isn't starting until the throttle is lifted. Or it's cutting spark.
 
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#2 ·
It does work, but I've never heard of doing this in the cold. Then again, it's rarely that cold where I live.
 
#4 ·
This is called "clear flood mode" which most FI cars do. It's not to cycle the oil and I would not do this unless you have flooded the engine with too much fuel. Typically this would only happen if you had leaking injectors or flooded it with cleaner.
 
#10 ·
Really no need to floor the pedal and pre-oil the bearings after an oil change regardless whether the filter was pre-filled or not. Assuming the car was run and the oil changed warm, there is plenty of oil retained in the bearings to support the crank/rods/cams etc. until fresh oil starts flowing. The hydraulic wedge is generated by the rotation of crank, cam, etc., not pressure or flow from the oil pump. You do need flow from the pump to replace oil that is flung out of the bearing, and to push out oil before it overheats (from friction) and begins to break down. But in the few seconds after an oil change, no big deal.
 
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