MicroSquirt.com read only forum (Jan.15,2018)

Hello!

I am running 2.3x firmware on my ms2... My problem is : when you put the car into gear (especially reverse) the motor wants to stop - unless you put in HEAPS of idle air (pwm type) ; then the thing wants to idle very high. The car is a 250ci 6cyl with a 'small' cam, ported head and (unfortunately) a standard stall speed torque convertor. I have tried alsorts of stuff (timing, pwm duty, etc.) and I cannot get 'the best of both worlds' that is, a reasonable idle speed in neutral and in gear. This problem is made worse if I load up the motor with the blower fan or headlights. Do I have to make a circuit to look at the neutral drive switch signal and increase the idle air intake or is there another fix I have not investigated?? Any ideas? BTW the thing goes like the 'hounds of hell' once you get off idle!

Thanks!

KEndall

KEndall,

Make sure to tune the ide VEs in both neutral and drive to get the minimum MAP kPa. That should allow the engine to idle happily when pulling from neutral to drive, though the engine might stager a bit for a second or two. Then tune the idle timing advance at both, so that the speed doesn't change too much when you pull the trans into gear. This may mean running more timing in gear (with a higher MAP kPa) than in neutral (with a lower kPa).

This may not help a lot if your converter is very tight - one thing that does help in that situation is to lower the idle speed (so there's less drag from the converter trying to stall).

If none of the above works, then you will either have to live with it (by increasing the idle speed in neutral), or make the modifications you describe.

Lance.