MAP sensor confusion

[c131frdave]

I've always had issues with my car being rich, and I think I finally figured out why. My MAP sensor isn't set right. But I'm confused on how to set it.

I'm using a Bosch 0261230042 TMAP. According to Bosch, the sensor has a range of 20kPa to 250kPa, or .2 bar to 2.5 bar.

I currently have it set to:

Map Sensor Linear: 200 kPa
Map Sensor Offset: 9.8 kPa
Map Sensor Linear B: 66.67 kPa

I believe, according to the Bosch literature, that the settings should be 250, 20, and 83.33 respectively, correct?

If so, I'm also a little confused about actual real-world readings. Someone who has a test bench with the exact same sensor reported the following:

1psi =1.92v = 6.9 kPa
5psi = 2.53v = 34.4kPa
10psi= 3.2v = 68.9kPa
15psi = 3.86v = 103.4kPa
20psi = 4.5v = 137.9kPa
25psi = 4.84v = 172.4kPa

Well, the thing is rated at 5V max, and when I plot it, the slope would suggest that at 5V, I would get around 190kPa.

So which is it? 250kPa or 190kPa? What numbers should I use to program the Map sensor calibration? Thanks!

[c131frdave]

Edit: I should have noted that my car has a TVS supercharger on it. Duh. Using the 2 bar OS.

[DWC]

Dave,
What are the volts of your MAP sensor key on motor off?

[c131frdave]

You just want ambient? Like 1 bar? (or close, depending on the weather) I'll check it out in the morning and let you know. Thanks for the reply.

[DWC]

Need you to set up a PID that logs MAP volts
1 bar will read around 5v key on and a 2 bar will read about half that (Key on)

[DWC]

Just want to make sure you have a 2bar MAP

[c131frdave]

Okay. I had a job interview today and didn't have time for it. I'll do it tomorrow first thing.

[TwoFast4Lv]

I had this recently on a 13 camaro. Had a two bar map and a one bar tune. This is the tune that came with the blower. A TVS2300 also

[c131frdave]

Okay, I did a scan, but I'm not sure I got the information you were after. I'm a noob, if you haven't figured it out yet. lol

I couldn't find a PID that was Map voltage, but what was interesting was that the Map sensor was reporting 98kPa, but the 2 BAR MAP GM on the bottom part of the chart said 65.65 kPa. So maybe I'm in the same boat as TwoFast4Lv?

scan.jpg

[c131frdave]

Also, note that I was wrong about my settings. The file I thought I had uploaded was different than the one that was in the computer. I downloaded the tune file, which is attached to the post above. The MAP settings are:

MAP Sensor Linear: 256kPa
MAP Sensor Offset: 5.2kPa
MAP Sensor Linear B: 85.33kPa

I uploaded this a while ago, and I'm guessing that it was probably a tune I found somewhere that was supposed to be similar to my car (supercharged 6 liter LS motor).

What I need to do is start from scratch, but I don't think I can get a good tune unless all of the sensors are calibrated to what the computer expects...


I just drove to Walmart to get some stuff, and hammered the throttle, something I really don't do much anymore because I'm old..., and black smoke billowed out the exhaust. I'm way rich. I got a new wideband sensor but I don't want to install it until I'm ready to tune.