Closed loop PWM problem (for me)...

karlo · Post by **karlo** » Sun Oct 21, 2007 9:38 am

I've got some of the same issues as mattd860. It's most noticeable when the engine is cold; I get a slight hiccup when I get on the throttle after idle.

I made a change in the code to not set idle DC to the closed DC when you get on the throttle. Instead it will just leave the idle DC as is.

It seems to work pretty well for me. Off and on idle response seems smoother and as a side effect, overrun is a little less aggressive--it doesn't pull as much vacuum any more.

Post by **muythaibxr** » Sun Oct 21, 2007 9:48 am

As I said, I'm going to make it slowly close the valve in 2.1.

I'm also going to make each of the PID values settable to a "high" IAT value, and a "low" IAT value... so you can have IAT-based PID values.

Finally, I'm working on the stepper motor version of this today and tomorrow as well.

I spent today setting up my MS to test with the IAC, and testing it in current modes.

Also spending some time figuring out how the code controls the stepper motor. My own valve only works in "always on" mode, which I find odd, so I'm digging through the code looking for what that does. Once I figure everything out, and I'm confident that it's working the way I think it should, I'll add support for it to my closed-loop algorithm.

Ken

hassmaschine · Post by **hassmaschine** » Mon Oct 22, 2007 11:13 am

karlo wrote:I've got some of the same issues as mattd860. It's most noticeable when the engine is cold; I get a slight hiccup when I get on the throttle after idle.

I made a change in the code to not set idle DC to the closed DC when you get on the throttle. Instead it will just leave the idle DC as is.

It seems to work pretty well for me. Off and on idle response seems smoother and as a side effect, overrun is a little less aggressive--it doesn't pull as much vacuum any more.

increasing the idle activation RPM adder worked for me. there is other undersireable behavior caused by this work around, but it's not nearly as annoying as having the car stall/buck during every launch.

Looking forward to the updated PWM code! I finall got my car to run pretty well with EAE enabled.. just gotta fine tune it now, and then I'm on to ignition timing and finally more engine mods.

Post by **muythaibxr** » Mon Oct 22, 2007 11:51 am

Just a note, changing ignition timing could lead to some retuning on fuel.

Ken

hassmaschine · Post by **hassmaschine** » Mon Oct 22, 2007 12:23 pm

yeah I realize that.. But I finally have my AFR target table dialed in pretty well so retuning the VE map is pretty easy. that and I've probably retuned it 100x by now, so I'm used to it. :p