How to use anytrim with fuel pressure sensor on LPG?

[mr_g]

LPG doesn't have linear fuel pressure regulator like gasoline, and also, pressure regulator is slower than MAP changes...

normally LPG piggyback that controls LPG injectors has a LPG pressure sensor that is used to compensate this kind of a issues with fuel pressure regulator...

I'm not using LPG piggyback anymore as VEMS is fully running the car both on LPG and gasoline, but this issue is present and compensated with closed loop...

So I was wondering could I use this pressure sensor and anytrim for this issue? The problem is that LPG pressure sensor is absolute pressure sensor, not relative one, and anytrim is based on relative reading...

[mr_g]

So I would need aritmatic operation done at VEMS with simple add operation:

anytrim_calc_input = LPG_press_abs - MAP

But VEMS doesn't have this options..

[GintsK]

I have question regarding this. LPG is injected in gas state of matter. So both pressure AND temperature has hard influence on injected quantity. What about temperature compensation using VEMS?

[MWfire]

So I would need aritmatic operation done at VEMS with simple add operation:

anytrim_calc_input = LPG_press_abs - MAP

But VEMS doesn't have this options..

you can do exatly that.

[mr_g]

I have question regarding this. LPG is injected in gas state of matter. So both pressure AND temperature has hard influence on injected quantity. What about temperature compensation using VEMS?

There is pressure/temp sensor on LPG rail, but I don't use it on VEMS... So the AFR ratio isn't correct all the time, but that's why I'm running closed loop, so the AFR is corrected over wideband...

[GintsK]

I have question regarding this. LPG is injected in gas state of matter. So both pressure AND temperature has hard influence on injected quantity. What about temperature compensation using VEMS?

There is pressure/temp sensor on LPG rail, but I don't use it on VEMS... So the AFR ratio isn't correct all the time, but that's why I'm running closed loop, so the AFR is corrected over wideband...

Can trimming (multiplying) be done double: by pressure (should be line) signal and by temperature signal (should be curve)??

[gunni]

There is the option of multiplying using fueltrim1 and then again using fueltrim2

So you have Load(map or tps) , air temp, coolant temp, fuel trim 1 , fuel trim 2 for fundemental fuel algorithm