tunning MAT/CLT correction

[nathanhardy]

so what is the best way to tune this. I've been having a slight issue with my car leaning out as the outside temp has been getting warmer i do not seem to be having a heat soak issue at least not a extreme one.

[142 guy]

The MAT/CLT correction blends in some coolant temperature with the MAT. I believe that as the engine coolant increases in temperature, this will increase the MAT used in the fueling equation which will tend to raise the AFR. The X axis is I believe mass flow through the manifold. At low flows (idle) you have added a fair amount of correction which will tend to cause it to run leaner. Is that what you want to do?

The MAT/CLT is probably effective for an application that has the IAT mounted further upstream from the intake manifold and under a hot idle condition, is measuring an air temperature that is lower than the actual intake manifold temperature causing the engine to run with a lower AFR.

[nathanhardy]

So basically I tuned my car pretty well with auto tuning and the car has been great but since I put my ID 1000 is I've had some weird issue on being Mat correction and warm starting. It's almost like the ideal gas law is to aggressive and the crank pulse is to match due to the high injector deadtime

[suberimakuri]

You may be hitting 'non-linear injector flow' characteristics if this is at low loads with big injectors. Lots of videos and info out there on it.

[nathanhardy]

My thought was this and I was assured by ID that I'd be fine... But that was where I was headed wondering what I'll affects turn down my deadtime would have?

[lagos]

So basically I tuned my car pretty well with auto tuning and the car has been great but since I put my ID 1000 is I've had some weird issue on being Mat correction and warm starting. It's almost like the ideal gas law is to aggressive and the crank pulse is to match due to the high injector deadtime

I bet the problem problem is not with the gas law, but with the fact that your injectors are not doing what they are commanded to do.

Try this:
Highlight your idle cells and multiply them by 1.10. You just commanded 10% more fuel. Now look at your AFR, is the car running exactly 10% more rich?
If not, than you need to calibrate the battery voltage compensation value, under the injector deadtime menu.

[nathanhardy]

Okay I'll give that a try as soon as work gets back to normal ID said 1.069 for the dead time and .17 for the correction I figured the correction would be something injector based not car based?

[lagos]

Okay I'll give that a try as soon as work gets back to normal ID said 1.069 for the dead time and .17 for the correction I figured the correction would be something injector based not car based?

I noticed that the voltage correction is best tuned by allowing the car to idle with the alternator control cable disconnected. Then adjust that value until the afr is the same at 10v as it was at 14v. If that setting is wrong, your temperature corrections will be way off.