Decelleration Fuel Cut

[944Technologist]

> Hi List,
>             Under what condition is 'decceleration fuel cut' used?  Is
fuel
> totally stopped to the engine?

Nick,

This happens to be my specialty. In a Motronic under deceleration, and the
throttle switch closes, all fuel stops to the injectors. At a frequency of
about 1,600 RPM, fuel begins again gradually until you have a normal idle.
It is meant as a fuel saving device. It only occurs when decelerating and
the throttle switch closes.

In early 944 Porsches in the US, they miscalculated the frequency and made
it 1,350 with a 950 RPM normal idle. Fuel does not get started back up in
time resulting in drops in RPM as low as 600 RPM and a nasty engine shudder.
It happens every time you come off the gas and fortunately it is a small
percentage of 944s that are sensitive to it. Unfortunately, mine is.

FR Wilk
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