GM 3Bar 12219935 Values for Linearboost Function

[BoostedBeaver]

Good afternoon,

I am currently installing a MAP sensor into the EGR input on a 1990 V3 ECU to measure back pressure. I have wired in the sensor, drilled and tapped the manifold, installed a few feet of 1/8 copper tubbing and connected it all with fittings and a 2in piece of rubber hose. All that I have left is to make the sensor read properly.

I went to save my new pin assignments but a pre defined selection was not available for the GM (Delphi) 3Bar MAP with a part number of 12219935. I have tried logging the sensor using the linear boost function but have had no luck in producing the right numbers for the Min and Max Boost and Volts.

I found this thread were a member listed some info on another site. Once I converted the KPA numbers to PSIA, I entered the Min volts of 0 and Min boost of 6.27. I then entered a Max value of 5 volts and 45.47 PSIA. This produced a positive reading with the car on but not running.

I then found this post were a member actually posted the links to the Delphi product sheet. This sheet list some slightly different info. When converted to PSIA and input into link the numbers where Min .43 volts at 10.15 PSIA Max 4.94 at 43.51 PSIA. This also produced a number that was close but not 0 when the car was not running.

Does anyone have the correct values to input into Linear Boost to make this sensor work correctly? Or can anyone find something in the above resources that I am overlooking? Any help in solving this issue would be greatly appreciated. I would love to get some back pressure numbers on this bolt on HX35

 

[gofer]

If the number is is close to zero when the cars off then you need to double click the logged value in your log and adjust the altitude to tweak it to zero. Odds are you had the values correct, here's another table you can use...

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[BoostedBeaver]

The number was .2 with one of the sets of numbers but when I input the elevation for my area, it went to .4.

I will try some of the numbers from the chart that you have listed but do you know which 3 bar this is for? It looks to be the 1222#@!@#@ 3 bar which has better low end (vaccum) readings where as the 12219935 sensor has horrible low end making it a bad choice for SD.

Your advice and input is greatly appreciated,
Robert

 

[gofer]

This isn't specific to your GM MAP sensor but Dave does a great job explaining how to caculate settings for Linear Boost. Another aem 5 bar question

If I were you these would be the settings I'd try out for LinBoost, if you're reading close to 0 with the car off (atmospheric pressure) then play with altitude (increasing/decreasing it) until you read 0.

Min Volts : 0 v
Min Boost : 0.5 psi
Max Volts : 5 v
Max Boost : 45.68 psi
Altitude : ~150 ft.​

Like I said, if the MAP is logging close to 0 (+/- 0.5) then add/subtract from your altitude setting.

 

[BoostedBeaver]

Just to follow up, I input the settings in the screenshot below. This made the sensor read 0.0 with the ignition on and the engine not running.

The sensor maxes out at 30.2 PSI which it hit at two points during this run. This means that I am running 1.62 PSI of back pressure for every pound of boost or a 1:1.62 ratio. Not the best but better than I expected. You can view the results here.

Robert