MAF and B5001 Questions

[Dale]

Working on trying to get my car to idle after start properly as well as quit running rich.

When gathering parts, I figured all vortec mafs were the same, so I grabbed one off a 4.3l... then installed it on a 5.7l. Now after downloading a s10 4.3 tune, I noticed the b5001 chart is WAY different.

So question 1 is, does this chart need to side more with the CI of the motor, or side more with what the maf sensor came off of?

Q2:If it sides more with what the sensor came from, would it cause it to run rich, and not hold an idle after start?

Q3:If I change my b5001 chart to the 4.3 settings, is there anything else I should change tell I can afford the proper maf?

[SOMhaveit]

1. If you look around at tunes you will see that GM uses different values in the MAF table for the same part # in different applications. I don't know if that's directly related to Cubic Inch displacement. But clearly the MAF is not just an instrument to measure air flow/volume without other factors taken into account.
2. With my limited understanding of how the MAF works, if the MAF signal combined with the table in your tune is telling the PCM that more air is entering the engine than the actual amount, you will get more fuel than you need and you will run rich.
3. You don't need to change anything else just to try a table that was oem with the MAF you installed.

You are doing all of this with a wide band or something else beyond the narrow band 02's, right?

[Dale]

Since that post, I have tryed the 4.3 fuel chart, and completely disabling it. I got the best response "as it was". But I am still having problems with it starting.

Using stock o2 sensors as thats all I have. I am beyond my budget already on this project.