EMU Black how to calculate cranking fuel/ and how it works question

EMU BLACK / CLASSIC
1

how to calculate time to open injectors and how to understand
ENGINE START PARAMETERS

Batch all injectors When this parameter is checked all injectors squirt together at every ignition event

for example.
Found OLD injectors flow data in g per minute, rebase it to mg per ms.
Did same for NEW injectors.
Calc proportion and reduce cranking time by this proportion. Not complex…but very strange, why not use percentage from desired fuel calculation, and not force users to suffer?

Suppose i found and recalc this data, and retune cold starts… Аnd with the onset of cold weather, I realized that the engine needs more cranking fuel… But in
CRANKING FUEL table max value = 25.5, but i need 30. What should I do?
Of course, the simplest thing is on the surface: use batch all injectors. But how to recalculate? Divide all previosly tuned values by engine cylinders count? And in normal temperatures, get strange values of cranking, whitch is dramaticaly below normal idle injectors PW - this is fine? Or need use some logic in mind: “if temp higher than 20C, then not divide by engine cylinders” ? is there any advice on this matter?

1 Like
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I’ve encountered the same problem you talk about trying to dial in my E85 cold starts and still have decent starting when hot.
The way I got around it was use more prime pulse and less cranking fuel. That has its own challenges for a flex fuel setup as there is only 1 prime pulse table that isn’t blended between petrol and ethanol but it works well enough.
Would be good to see the ms units for starting enrichment changed to a % multiplier of the VE table like many other ECU’s use.