7427 - any idle tuning tips?

I've been playing with the constants (injector flow, displacement) to get my VE under 100 in all areas and I'm getting closer (BLMs sitting in the 150s instead of maxing at 172 during the last drive). Basic overall drivability is good. However, I have now picked up a significant surge at idle. It idled fine when I first started using the 7427.

I set up emulation and tweaked the idle VE table up and down working 1% at a time and had no change in the surging. This was using closed loop idle. The whole time I could see the BLM/INT changing as I made my adjustments so I know it was getting feedback.

I forced open loop idle (that is how my 7747 was set up) and by running through the changes I got it to idle much better, with still just a slight surge. But sometimes after a drive when I come to a stop I'll have a high idle with a surge.

Any tips for either CL or OL idle tuning?

1 Attachment(s)

Perhaps flattening out your SA table in the MAP and RPM cells around the area of your idle? It helped mine in OL.

Quote:

Originally Posted by PlayingWithTBI

Perhaps flattening out your SA table in the MAP and RPM cells around the area of your idle? It helped mine in OL.

Thanks I'll play with timing and see what it does.