I knew there had to be a catch somewhere, I would have to re tune what the this is bull












I guess I'm going to be ordering my air intake sensor monday.




1slowsilverado;
How bad is the hot restarts? and how long until it cools down enough to give a good reading?

 

Yelo: Good find, looks like I might just be on my way of ditching the MAF or sell the one that is on there know and gut the stock unit.

 

what g/cyl is it showing?
how does this correlate with your timing tables

ex. if youre only reading .08 g/cyl how does your timing look at lets say 4000 RPM?

then compare it to an old log with the maf in place at wot g/cyl
4000RPM

seems to me like there would be a huge jump in timing unless you adjusted your timing tables to compensate for only running one line
and possibly even unsafe with the higher values in the lower load areas
and the pcm thinking its at low load all the time

I think youre on to something good here
but I think its more to it in your situation than just freeing up the air a bit

 

The PCM would not think it is in low load all the time. The MAF is only one part of the equation for calculating airmass. With it out of place, the VE table is used entirely for determining what g/cyl is occuring.

 

Kano is right....if you set the MAF fail to 0hz the PCM will ignore it and go straight to using the VE table to calculate fuel.

 

No, he's postulating that since since your Histogram is showing all spark values in one row, that your PCM is running off of the .08 g/cyl column (row in HPT case) in the spark table and could be dangerous, as it is running low-load timing in high-load operation.

What I stated (paraphrased) was that with the MAF in place, the PCM uses a blend of both the MAF and VE table lookup value to determine what the dynamic cylinder airflow value is, which is what all spark table lookup is based on. With the MAF out of commission, the VE table is the SOLE source for the PCM to determine what airflow is in the cylinder. Therefore, using some g/cyl calculation derived from the MAF would be completely inaccurate. You need to log the correct PID that would show what the PCM is using for its calculations.

 

OOPS....I meant: dc_justin is right....Sorry guys

 

1. spark table is looked up based on dyncylair, not dynair/maf
2. dynair/maf can be converted to dyncylair, through the means of rpm
3. pcm doesn't care where it gets the airflow readings (ve/sd or maf or mix of them), just uses what it can.
4. dynair is to dyncylair what hp is to tq
5. dyncyl air has lousy resolution, but dynair has a lot of error inherent to the difficulty of measuring airflow. so which one you use is up to you, experiment and see which one yields more consistent results

 

OK that makes better sense

Yelo,
are you still runnin the ls1 intake?

 

Okay, so are we are back on track now?

Now the real question, are you feeling better response/power due to the freeing up air restriction OR you have being dynair/maf all along and now it is dyncylair?

BTW, KY BOB, this is exactly why I unplugged it along time ago. To make sure the pcm doesn't use it....AT ALL. I know all about how to zero the mail failure, even zeroing out the table. My IAT is in the Radix Blower.