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3.3 BAR GM/DELPHI map sensor offsets?
Posted: Mon Apr 17, 2017 11:59 am
by forcefed86
What is everyone using here? It says the offsets are supposed to be 33 and 333? Yet when I enter these values and check them against my calibrated MAP sensor ( PLX boost gauge). The results aren’t even close. Using shop air and a regulator I just couldn’t get this sensor to read correctly throughout the range. I run around 20-25lbs of boost mostly so form 15-25lbs Using -30 and 357 was pretty spot on and only a pound or so off at lower boost ranges. I don’t have a way to check the vacuum, but I assume it isn’t pretty. Whats the deal with these sensors? Did GM just tune around their crappyness? Or am I missing something?
Why no 3.3 bar map sensor drop down settings?
Posted: Mon Apr 17, 2017 12:05 pm
by forcefed86
Having issues getting this sensor sorted out. Just curious why a drop in OEM replacement sensor settings aren't available in the software?
I’ve read the offsets are supposed to be 33 and 333? Yet when I enter these values and check them against my calibrated MAP sensor ( PLX boost gauge). The results aren’t even close. Using shop air and a regulator I just couldn’t get this sensor to read correctly throughout the range. I run around 20-25lbs of boost mostly so form 15-25lbs Using -30 and 357 was pretty spot on and only a pound or so off at lower boost ranges. I don’t have a way to check the vacuum, but I assume it isn’t pretty. Whats the deal with these sensors? Did GM just tune around their crappyness? Or am I missing something?
Re: Why no 3.3 bar map sensor drop down settings?
Posted: Mon Apr 17, 2017 12:48 pm
by jsmcortina
What sensor are you talking about?
Until you are confident that your calibration values are accurate - don't use it.
James
Re: Why no 3.3 bar map sensor drop down settings?
Posted: Mon Apr 17, 2017 1:28 pm
by forcefed86
AC Delco P/N 213-4658, GM P/N 12623671 formerly GM P/N 12215049 and 16235939. 3.3 BAR sensor
Old PN data sheet
http://www.powerandsignal.com/docs/Prod ... 215049.pdf
Link to new part
http://www.gmpartsdirect.com/oe-gm/12623671
Re: Why no 3.3 bar map sensor drop down settings?
Posted: Tue Apr 18, 2017 6:52 am
by Matt Cramer
The old part data sheet would indicate 33.3 kPa at zero volts and 366.7 kPa at 5 volts.
Re: Why no 3.3 bar map sensor drop down settings?
Posted: Tue Apr 18, 2017 7:00 am
by forcefed86
Matt,
I’ve tried that and the values are worse than my selected values above on -30 and 357. THough at lower pressures (under 15) it seems more accurate than my settings. It’s almost like the sensor isn’t linear?
Couple forums mention since this sensor is used on diesel applications that the vacuum readings are poor at best. No idea if that information is reliable though.
A vendor told me the factory ecu settings are:
Scalar: 617
Offset: 11
Not sure how that translates to the MS3 parameters?
I’ve verified my PLX devices boost gauge with a calibrated gauge and it appears spot on. So I’m certain it’s the 3.3 bar sensor that’s the issue.
If I can’t get this to work, I’m looking into the LS9/ZR1 3 bar sensors. (12592525) They have a better reputation anyway.
Thank you!