Decelleration Fuel Cut

[Ade + Lamb Chop]

On 20 Jan 2001, at 16:38, Nicholas Parker wrote:

> Hi List,
>             Under what condition is 'decceleration fuel cut' used?  Is
>             fuel
> totally stopped to the engine?  How can you tell (via MAP, TPS, RPM
> whatever) if the engine is stealing torque(braking - absorbing power)
> versus producing torque for either constant speed or acceleration?  Is
> cutting fuel always appropriate during engine decelleration? (I'm
> guessing no, as you could be decelleration while going up a hill
> decelerating slower than gravity would accelerate you in the reverse
> direction so theres alway a load on the engine!)

On Minis if the throttle is closed (TPS) and the revs are more than 
1600rpm then it shuts the fuel off until the revs drop to 1600rpm. 
However this system isn't perfect. If you are in 1st and doing say 
2krpm eg in traffic.. The switch point between getting some fuel 
(throttle slightly open) and no fuel (throttle closed) is quite sharp. I 
have heard that some systems have a road speed sensor on them 
too so you only get fuel shut off above Xrpm and Xmph with the 
throttle closed

Ade

ICQ. 75653589
www.adesite.co.uk
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