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C R A N K _ F U E L _ P U L S E W I D T H _ M U L T I P L I E R _ V S _ T I M E

(

8191.88, 1 )

(

0, 1 ) ( 0, 1 )

(

0,

(

0,

1 1

) )

(

0,

1

)

This function is used to modify the CRANK_FUEL_PULSEWIDTH_VS_ECT values. The x value is the time in seconds, the y is the multiplier. This allows across-the-ECT-range pulsewidth changes without having to enter new ECT-dependent pulsewidths.

This is useful for reducing the pulsewidth when using larger injectors. This dramatically improves engine starting, and the surge that comes right after starting with larger injectors. I suspect the surging is burning latent fuel from a wet manifold that was over-doused with fuel. Set the multiplier in proportion to the size of the new injector.

For example: If going from 19 to 36 lb/hr injectors. You might use the following function. 19/36 =c CRANK_FUEL_PULSEWIDTH_MULTIPLIER_VS_TIME

( 8191.88, 0.53 ) ( 0, 1 ) ( 0, 1 ) ( 0, 1 )

( 0, 0.53 )

( 0, 1 )

The smallest pulsewidth appears to be about 2ms. A lower multiplier will not lower the pulsewidth below 2ms. However, a zero multiplier produces a 0ms pulse.

Using the 0 multiplier you can introduce a period where the engine is cranking, but the fuel injectors are not introducing fuel—just like WOT cranking without holding the throttle wide open. This can be useful for cars running very large injectors, such that a 2ms pulsewidth will still flood the engine on starting.

For example: I use this on my car with 50 lb/hr fuel injectors. Without this setting, it will not start when its warm—I will have to start it at WOT to clear the flooding

C R A N K _ F U E L _ P U L S E W I D T H _ M U L T I P L I E R _ V S _ T I M E

    • ( 8191.88

      , 0 )

    • ( 1.5

      , 0 )

( 3, 0 ) ( 1.5, 0.35 ) ( 0.75, 0 ) ( 0, 0.35 )

This function would gradually, over ¾ of a second, reduce the injector pulsewidth from 0.35 full value to 0. Then from ¾ of a second to 1.5 seconds, no fuel would be delivered. From 1.5 seconds to 3 seconds fuel delivery would decrease from 0.35 full value to no fuel. From 3 seconds to 8191.88 (infinity in relation to cranking), no fuel would be delivered. This would clear any flooding condition as I crank beyond 3 seconds.

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