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Overrun fuel cut and ignition retard


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Hi, im new to using Link ECU as I bought my car from someone else. The ecu was already installed by the previous owner and tuned. After reading the help files, I found out that many of the setting tables are not looked into or not tuned right for example- Charge temp approx, overrun fuel cut, closed loop lambda to name a few.

I have few questions:

1. my overrun fuel cut settings shows torque reduction is 0.52s and ignition retard is 0. The help file says

Ignition Retard

To help smooth the transition as the fuel cut turns on and off, the ECU will progressively retard the ignition timing prior to cutting fuel.  The ignition timing will then be progressively advanced back to normal after the fuel has been restored. Changing the Ignition Retard adjusts the full amount of ignition retard the ECU will use. The amount of time taken to introduce and remove the ignition retard is controlled by the Torque Reduction/Introduction Time setting.

The minimum rate of change for the ignition trim is 5 degrees per second.

Is this a correct setting or the ignition retard should have some value on it?

2. What is the best way to tune the Charge approximation table?


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I've found about 10 deg in the ignition retard gives a nice smooth transition in and out of fuel cut.

The charge temp approximation table is a tricky one and it takes a bit of time to get it right. It will also have an effect on the fuel table so this really needs to be done on a dyno or road tested with AFR feedback. If its been tuned in Traditional fuel mode then you don't need to use it.

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Can I just say thanks for posting this. I have had an ongoing issue for a long time which has been too minor to fix but still caused immense irritation. There was basically a very soft 'shudder' coming off or coming back onto throttle. I thought this was due to be botching the accel enrichment or my lumpy cams. I put 15 degrees per second in for ignition retard and set reduction/introduction time to 1 second. Has completely smoothed out my throttle transitions. 

I am extremely grateful for having this solved and frustrated beyond belief for not having looked at these settings sooner knowing it was the overrun transitions where the issue was occurring. -_-  

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Thank you Leiden for your input. Learning how to tune the Link ecu has been so far challenging but surely a time well spent. Im supprised to see that so many tables like the Idle ignition timing, charge temp approx and some other minor settings have been overlooked by the tuner before. Reading the help file really gets you to check everything that your vehicle needs. 

Hi Sheik, hope it solved your problem for good. 

I had another issue I just found out that regarding the open loop idle that simply winds up and down when I turn off the idle ignition timing. Any thoughts how you manage to tune your idle?

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