Monday 18 March 2013

ECU Injection corrections

A little reasonable weather so time to make inroads on the ECU settings.

The engine has been running fine, but starting is poor and tick-over once up to temperature poor.
I went through the IACV setup one more time as per Emerald documentation 

Then adjusted the Injection corrections - the key table which helped was changing the Coolant temp correction.

Originally to get the engine started (without accelerator) I increased the initial injection prime - what I hadn't touched yet was the coolant temp adjustment - this increases injection by a percentage amount depending on coolant temp - by manually adjusting injection to get a clean run/idle you can then calculate the percentage increase needed at various temperature points;

So far I have one data point:  +11% @ 92º    

Even using just this single data point and calculating a straight line across the others makes a huge difference - waiting for the engine to cool now so I can get a few more data points. Needing an overall increase at this coolant temp may well be an indication the whole map needs revising - possibly my OEM fuel pressure gauge delivers slightly less juice than the engine GBS had mapped.

Update - I'm going to have another play with ECU settings - probably shift this +11% to the main map rather than on the temperature ajustment map since at 70º+ there shouldn't really be an across the board (all sites) increase.

The challenge for the novice (me) is fuel & air have to be in balance to get a smooth run & its difficult to tell which variable to change - i.e. more injection works up to a point then you need to balance with more air or it just richens the mixture and goes lumpy; similarly - more air generally increases revs until you go past that sweet spot and its over lean.


I will update the ECU page as I settle on particular settings.











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