Map sensor problem

[pommie02]

up until now i have not been using a map sensor, as i am using aplha n.
when i came to calibrate my GM 3 bar sensor at all went horribly wrong, i used the calibration settings as in the sensor calibration. but this didnt alter the position of the gauge , so i made up some figures which lowered the lower setting with the engine running. but when i tried to alter the higher range the bike would not restart, i had to disconnect the sensor to start the bike....any ideas

[Matt Cramer]

Sounds like your map is a bit off. It may just take some changes to your VE table to get it running now that you've gone speed density.

[pommie02]

what i cant work out is why the bike would not start...
how can the map sensor affect this ?

[Matt Cramer]

As soon as you go over the cranking RPM, it uses the MAP sensor to calculate fueling. if the speed density VE table is far enough off, this can kill it as soon as that happens.