map sensor
03-24-2003, 02:16 PM
#1
3.0 BAR
Thread Starter
Join Date: Jan 2003
Posts: 4,401
map sensor
ok so last night were cruising home me and my buddies and thier all speeding and leaving me at the back of the pack so i decide i need to show them what boost is all about!! im in fifth and instead of downshifting i just floor it and man 9lbs of boost jsut feels sweeeeet!!! 
anyways as soon as i caatch up i get and cel and my car starts sputtering and bogging down , at this point im shitting it and swearing up and down thinking my ---- is blown. so we pulll over and the car is runing rough. its was a code3Map sensor. so i guess my afc settings arent to good. i just reset the ecu and took off like nothing ever happen. i definately got the ---- scared outta me.! anyways 1-4k is at -39%
4500 is -38
5000 is -37
6000 is- 36
7500 is- 35
i was probably arout 5000rpms when this happened, any recommendations on my settings on the safc? here are my specs d16a6, t3, 450cc injectors, walbro255 intank, runing 9lbs, thanks for any tips.
anyways as soon as i caatch up i get and cel and my car starts sputtering and bogging down , at this point im shitting it and swearing up and down thinking my ---- is blown. so we pulll over and the car is runing rough. its was a code3Map sensor. so i guess my afc settings arent to good. i just reset the ecu and took off like nothing ever happen. i definately got the ---- scared outta me.! anyways 1-4k is at -39%4500 is -38
5000 is -37
6000 is- 36
7500 is- 35
i was probably arout 5000rpms when this happened, any recommendations on my settings on the safc? here are my specs d16a6, t3, 450cc injectors, walbro255 intank, runing 9lbs
, thanks for any tips.
03-24-2003, 06:14 PM
#2
3.0 BAR
Join Date: Dec 2002
Posts: 3,828
Re:map sensor
It's like this
At -40% you can boost higher, but it runs leaner than at -35%.
with the -40% you are able to boost to 10-11 psi so I thing that setting at -37%is just at the limit for boosting 9 psi....so when hitting 9 psi or higher where you are set at -37% the map will read past 1 bar and the map signal to the ecu will be higher then normal like when boosting without the AFC hack...and giving the CEL.
Try to lean it out at 5000 rpm and up begin with -38% and see how much you can lean it out before going lean.. well -40% would be the limit though.
At -40% you can boost higher, but it runs leaner than at -35%.
with the -40% you are able to boost to 10-11 psi so I thing that setting at -37%is just at the limit for boosting 9 psi....so when hitting 9 psi or higher where you are set at -37% the map will read past 1 bar and the map signal to the ecu will be higher then normal like when boosting without the AFC hack...and giving the CEL.
Try to lean it out at 5000 rpm and up begin with -38% and see how much you can lean it out before going lean.. well -40% would be the limit though.
03-25-2003, 06:59 AM
#6
3.0 BAR
Join Date: Dec 2002
Posts: 3,828
Re:map sensor
hmmmmm with bigger in jectors you would be fludding your engine...too much fuel and you will get a CEL.
By putting bigger injectors and setting the afc at -40% etc. you're fooling the ecu it will read 1 bar atmospheric pressure from the map sensor when you're at 10-11 psi, bacause the voltage the map sensor sends to the ecu is lowered by 40%, making the injectors deliver less fuel(that's why you need bigger injectors) and fooling the ecu that you're not boosting so you can run boost.
By putting bigger injectors and setting the afc at -40% etc. you're fooling the ecu it will read 1 bar atmospheric pressure from the map sensor when you're at 10-11 psi, bacause the voltage the map sensor sends to the ecu is lowered by 40%, making the injectors deliver less fuel(that's why you need bigger injectors) and fooling the ecu that you're not boosting so you can run boost.
03-25-2003, 09:48 AM
#7
0.0 BAR
Join Date: Mar 2003
Posts: 30
Re:map sensor
just curious cause im not getting past 5200rpms. it feels like im gettn fuel cut or somethinng between 4800rpms and 5200rpms cant figure out what it is. tried -40 percent and even plus 15 and still at those rpms the car just starts to sputter. any thoughts
