Can One Set Lag for MAP

[Lazabby]

I don't have a TPS so my Megasquirt controls fuel based upon MAP. The only problem is the MAP reading is a split second ahead of fuel input so the car wants to bog down when accelerating from a stop. Is there a way to set up a lag for the MAP so that the fuel input is more in sync with the MAP?

[Matt Cramer]

This really sounds like the car needs a bit more AE tuning. You don't want to delay the MAP reading; what you want to do is make the fuel come in faster.

[muythaibxr]

Which means you want *faster* MAP response and some AE.

[Lazabby]

This really sounds like the car needs a bit more AE tuning. You don't want to delay the MAP reading; what you want to do is make the fuel come in faster.

I've got the AE up as much as I can. Any higher and it's hard to hold a steady speed without surging. Any tips?

Shannon

[Matt Cramer]

[Lazabby]

Sorry for the delay in getting back to this. I need to set a lag for the MAP so that the fuel can be entered at the same time as the air (if that makes sense). When I'm at a complete stop, and then begin to accelerate, the air comes in a split second before the fuel and the car wants to bog down due to the car running briefly lean. Attached is a log and my current tune. Go to about 1150 to see the activity. What should I tweak to eliminate the bogging down. The car does not have a throttle position sensor.

Shannon

2016-10-02 Shannon Tune.msq

2016-10-02_17.33.44.msl

[Matt Cramer]

The AE frequently triggers much later than the throttle starts opening. Try a smaller MAPDot threshold value to make it trigger sooner. However, the MAP signal is not always even, so there are limits on how far down you can set the threshold before it starts triggering. Installing a TPS may be a better plan.

On an unrelated note, it looks like you're on an obsolete beta code. Consider switching to the latest stable release.