so when my engine was built and installed the builder used an FD 2bar map sensor ensted of a 3bar like i requested, needless to say when i was checking the map tracer (sp?) i noticed at 14psi it was reading the bottom line on the grid, now i'm wondering, i had an akward hessitation where it felt as if the engine cut out at around 6600rpm in 4th gear, the boost guage read 14.8psi peak, i noticed on the knock reading it was 5points higher then normal, could it be a power FC related issue or is there something more?, could anything have happened?, would detonation be a factor or possibility?, for a short while after it would not idle properly and when it did it idled very lean, 16:1 AFR give or take, normally it's at 12.9:1 yet seems ok today once i got to work....

i have a BNR3 turbo on a large street ported engine with the power FC, not sure if that information is needed or not....

 

Also, when the reading drops past the lowest cell on the PFC what occurs, does the fuel default to the lowest cell or is it as if there was no tune?

 

Both sensors only put out a max of near 5 volts. A 2 bar will put out 5V at a lower pressure than the three bar.

So if your sensor setup and MAP REF scales were setup for a three bar instead of a two bar, what happens?

 

It's setup for an FD map sensor.

 

I don't think your problems described are related to the map sensor. From what i have seen the stock sensor will read up to around 17 psi. To answer your last question it will use the last row of cells for the tune. It does not just go to zero.

 

map sensors are rated with positive and vacuum pressure
that is, a 2 bar map sensor, is really a 1 bar positive pressure sensor
because it reads -1 bar to +1 bar. so if you want to run 1.5 bar boost, you need a 3 bar map sensor as 1 bar is vacuum or (negative pressure) and 2 bar positive

this would explain why yours flat lines at 1 bar, because, technically its the most it can read in positive pressure

 

hrm, i dont have a clue as to what happened with my car then....