95 LT-1 Idle Cell Comparison - Humidity?

[kur4o]

I should say you are running really lean on startup.
Don`t forget you are spraying cold fuel straight in the cylinder, There is not enough time to evaporate and it should be extra rich to run smooth.
The engine doesn`t make enough power and wants to stall, drawing more unused air, making things worse, that`s why you are seeing 160 iac and high map and low rpm. The engine is fighting to run.
It gets a liitle better when the 02s start to climb.

Compare that with high humidity and possible weak spark not having enough energy to ignite the lean humid mixture.


Engine is not making enough power to stay running.

Maf doesn`t play at engine starting at all it is the crank VE table that matters.

And that 02s are like frozen they should be jumping like mad from rich to lean. There is something very bad happening there. Load the stock CL settings and see if there is some improvements.
If you still can`t dial the idle closed loop, I have a remedy called Open loop idle patch.

You should also investigate the controversial readings between narrowband 02s and wideband readings.

[spfautsch]

I should say you are running really lean on startup.
...
The engine doesn`t make enough power and wants to stall, drawing more unused air, making things worse, that`s why you are seeing 160 iac and high map and low rpm. The engine is fighting to run.
It gets a liitle better when the 02s start to climb.

Compare that with high humidity and possible weak spark not having enough energy to ignite the lean humid mixture.

Engine is not making enough power to stay running.

Now you're making sense. I'll give it a try.

Maf doesn`t play at engine starting at all it is the crank VE table that matters.

I understand that - the startup / cranking fueling tables are well out of the picture after the first 8-12 logged frames of startup. But immediately after those initial frames the MAF and Injector constant pretty much run the whole show. Agreed?

And that 02s are like frozen they should be jumping like mad from rich to lean. There is something very bad happening there.

As I mentioned previously, I think I've raised the injector constant enough to cause this. In the first post, both frames (43kpa and 48kpa) were taken with 42.036 for the injector constant. It's currently at 43.547. I suppose it's possible the injectors flow less than 42, or my dwell problem was wholly to blame and I've moved it from rich (or ideal) to lean fighting what I believed to be a problem of too much fuel and not enough air.

Load the stock CL settings and see if there is some improvements.
If you still can`t dial the idle closed loop, I have a remedy called Open loop idle patch.

If you would, take a look at these logs and critique the closed loop behavior. The 43kpa idle frame was taken from one of these logs, and the only closed loop setting I've changed since is the Stoich AFR Target.

You should also investigate the controversial readings between narrowband 02s and wideband readings.

I'll worry about that another time. As discussed in other threads it's using the D27 analog input with the default ADC output settings. It's also mounted about 18" downstream from the narrowbands in the X pipe. It doesn't get hot enough from idling alone for me to use for calibration purposes.

Edit: Acutally the x pipe is more like 24" downstream of the header collectors.