Why no 3.3 bar map sensor drop down settings?

For discussion of Phil Tobin's Tuner Studio software (Only about the tuning software itself, not about how to tune or firmware features)

Moderator: LT401Vette

Post Reply
forcefed86
Experienced MS/Extra'er
Posts: 226
Joined: Wed Aug 13, 2014 7:08 pm

3.3 BAR GM/DELPHI map sensor offsets?

Post 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?

Image
forcefed86
Experienced MS/Extra'er
Posts: 226
Joined: Wed Aug 13, 2014 7:08 pm

Why no 3.3 bar map sensor drop down settings?

Post 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?

Image
jsmcortina
Site Admin
Posts: 39585
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK
Contact:

Re: Why no 3.3 bar map sensor drop down settings?

Post by jsmcortina »

What sensor are you talking about?

Until you are confident that your calibration values are accurate - don't use it.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
forcefed86
Experienced MS/Extra'er
Posts: 226
Joined: Wed Aug 13, 2014 7:08 pm

Re: Why no 3.3 bar map sensor drop down settings?

Post 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
Matt Cramer
Super MS/Extra'er
Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: Why no 3.3 bar map sensor drop down settings?

Post by Matt Cramer »

The old part data sheet would indicate 33.3 kPa at zero volts and 366.7 kPa at 5 volts.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
forcefed86
Experienced MS/Extra'er
Posts: 226
Joined: Wed Aug 13, 2014 7:08 pm

Re: Why no 3.3 bar map sensor drop down settings?

Post 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!
Post Reply