ECU Battery comp, Lambda and Cold start

Successful ECU tweaking session this morning, major changes listed.

All results documented on the ECU page

Battery compensation

The changes to the power distribution gained me a good 0.5-1.5volts which in turn threw the mixture off, slow idle lost etc. The culprit I believe to be an over eager battery voltage compensation table which was still on default values.

The steepness of this curve was noticably changing the mixture as the idle hovered between generating 13.2 and 14volts, 0.3ms doesn't sound like much but its somewhere on the order of 10% of the total injector duty cycle. I levelled the area betwen 12-14 volts and changed the overall shape.

A new avenue of learning opens up - the curve is directly related to the injector performance and should be documented against each type so my next task is to track down the stock battery compensation curve on a Bosch 0-280-155-820 injector!

Lambda

Some fine adjustment on correction gain and update frequency minimised the overshoot on lambda corrections letting it lock on at slow and fast idle. This was trial and error adjusting gain and frequency independently, slowly, to find the sweet spot of response vs. overshoot. I also checked the calibration on the Spartan2 while I was there - all still spot on.

Raised the coolant temp above setting so it doesn't fight with the cold start injection adjustments.

I smoothed out the areas around the MOT pass points and adjusted to closed loop, I dont want the ECU automatically/permanently adjusting mixture in the idle zone. Fast idle on adaptive until I've done some miles and it learns.

Cold start

Revisited cold start, the curve is the right shape, I just shifted it to last longer by changing the engine turns against each row. She starts without any throttle now ~7-10º ambient air temperature.

The curve stays higher longer for the first 120 turns, same as holding a manual choke out for around 8-10 seconds.

...and a new blue temperature driven adjustment keeps the mixture relatively rich until the engine is warm.

Start is good, slow idle is rock solid, just need some more driving to train the map.

Update - 6th April - tweaked battery curve and the target AFRs, needs a run now for everything to settle in.