My son bought an audi A3 1.8T with an EMU Classic installed (this is my first experience with ECUMaster). Prev owner had 2 maps - one for E85 and one for 98 octane. It has been running great on both maps (ofcourse with correct fuel) until now when cold weather arrived. Now we only run 98 octane for the cold season. Injectors are quite large, 1200cc, but it runs good at idle and at speed. Only start ups in the cold are a problem. Sometimes It only catches a bit but never starts. But ones started there is no problem starting again.
So I have been trying to understand how fueling at cranking works. From what I can tell only cranking fuel which is pulse width in ms should be in play. ASE and WUE should not come into play until RPM is above the cranking threshold. This should mean that I should see in the log for injector pulse width the same number as I have in the cranking fuel table, right? I am not.
I have 2ms in the cranking fuel table and I am seeing over 4ms pulse width when I am under the cranking threshold turning over the engine.
If I set the cranking fuel to 0ms I still see above 2ms injector pulse width so there is no scaling table somewhere changing the cranking fuel. (WUE and ASE are both set to 100% for this test and should not change anything at all)
So where is this extra pulse width coming from? Is this calulated from the VE table and then the cranking PW is added on top of this this?
Tried something else today.
There is a table called “Fuel TPS scale” under engine start which according to the help menu should work as a flood clear. It does not.
I have a curve that goes to 0 at 100% throttle. If I completely press the throttle pedal during cranking (TPS shows 100%) my expectation is that injector pulse should go to 0ms. It does not. It only seems to remove the 2ms from the cranking fuel.
I also tried setting the VE table to 0. This does nothing to the injector pulse width at cranking.
Right now I am thinking it is the injector calibration. I don’t know what injectors are in this thing but there is an injector calibration table that adds 1,9ms at 10v which is about what I see for battery voltage in the log when cranking. If this is the case I guess this calibration duty cycle is added regardless if the cranking fuel is 0 or that the TPS is at 100% which should cut fuel. And if this is so I guess the calibration data for the injectors is off.
I threw in some Bosch 396cc injectors I had laying around and I can atleast get this thing to start reliably in the cold now. I’ll have to let it get real cold over night a few more times before I can call this fixed though.
I just could not get the 1200cc injectors to cold start reliably. It injects way too much fuel, no matter what I did. These are some sort of modified bosch injectors witha part number 0280 158 xxx. The last three are blured/scratched so I guess someone modifies these to get 1200cc out of them.