ECMlink GM MAP reads vacuum with car shut off

[okm12346]

Im trying to make the transition to SD and I have the 3 bar GM Map sensor feeding on the MDP sensor pin. The thing is that the log reads -2.3 inches of vacuum with the engine off. Then idling it reads -16.5 inches of vacuum and my in-car gauge reads about -20 inches. Now I know theres a option where I can set my own values for MAP sensor (user defined) or I can make it as a linear MAP and then do the same thing and set my own values. Am I going the right way or maybe I can get voltages from 3bar GM Map Load/volt charts.

 

[okm12346]

here are the pics

 

[taylork057]

my 3 bar reads .1 at KOEO.. yours is little far off. Bad sensor?

 

[okm12346]

IDK its brand new sensor. unless it was faulty it has zero running time

 

[enriquez2000]

Im trying to make the transition to SD and I have the 3 bar GM Map sensor feeding on the MDP sensor pin. The thing is that the log reads -2.3 inches of vacuum with the engine off. Then idling it reads -16.5 inches of vacuum and my in-car gauge reads about -20 inches. Now I know theres a option where I can set my own values for MAP sensor (user defined) or I can make it as a linear MAP and then do the same thing and set my own values. Am I going the right way or maybe I can get voltages from 3bar GM Map Load/volt charts.

whats your altitude... up here at milehigh we can be off up to 2 ticks on a map sensor because Absolute pressure is not 0

-20 on a zeroed out gauge would read -16.59 at 5280ft.. check it out on the calculator here... MAP sensors can mess with your head if you dont understand the altitude that goes with it. http://www.mide.com/products/slamstick/air-pressure-altitude-calculator.php