Map sensor plug?
- Thread starter dvernst
- Start date
Jan Larsson
Active Member
- Joined
- Nov 22, 2001
They all got them from the factory. If I remember correct there's a resistor on one of the wires in there ... not sure why?
It reduces voltage applied to map from 5 to 4.6. The engineers goofed when they made the instrument panel gauges.
Reason you take it off is to get full resolution from the sensor.
Now.. GM made an adapetr harness for new sensors used on the TTA. The wiring flipped on the terminals for a 3 bar MAP. So you cannot plug in a new 12223861 3 bar MAP into an 1989 TTA without the harness GM sells that flips the +5 and Ground wires to it.
So technically there are two plugs. One to calibrate the 3 bar to dash,and the other that didnt come with the car to adapt the newer style 3 bar to the TTA.
Reason you take it off is to get full resolution from the sensor.
Now.. GM made an adapetr harness for new sensors used on the TTA. The wiring flipped on the terminals for a 3 bar MAP. So you cannot plug in a new 12223861 3 bar MAP into an 1989 TTA without the harness GM sells that flips the +5 and Ground wires to it.
So technically there are two plugs. One to calibrate the 3 bar to dash,and the other that didnt come with the car to adapt the newer style 3 bar to the TTA.
So if you take it off to get full resolution from the sensor how do you get the Powerlogger, and gauge to read right? Thanks...
You'll need to run two sensors. As the calibration will be off for either.
Who cares about the factory gauge as it only reads to 20 PSI
It still works just not accurate. Not like it ever was or is usable.
HAHAHA are you kidding me????? Guys, I have had my alky kit going on 5 years now and I didn't realize this. My powerlogger still reads accurate I think and that is what I look at.
When I go down the track I pretty much launch and worry about keeping it straight. I check to make sure my alky light is green in the burnout box. I know my car isn't that fast, but how do you guys watch your gauges??
Jason
Mine reads really close too. Probably within a lb or 2 max of the manual gauge. I was tempted to take the plug out and try it. But after reading dvernsts post maybe not. :tongue:
I will give it a try. I am curious too. Also I was comparing logs with my GN and my friends GNs and the voltage at the MAP seems on par with what the GNs are reading at comparable boost levels.
Green wire on 3 bar is suppossed to show 1.6 volts normally. On the TTA with the added resistor its about 1.5 volts. This is KEY ON engine not running.
So if your green wire measures 1.5-1.6 volts there is no way it will show 17 PSI on your dash unless your factory boost gauge gave up the ghost.
Green=center pin on all harnesses.
So if your green wire measures 1.5-1.6 volts there is no way it will show 17 PSI on your dash unless your factory boost gauge gave up the ghost.
Green=center pin on all harnesses.
