VEMS Community Forum

VEMS => Configuration => Topic started by: fivepoint6 on November 08, 2015, 09:01:32 pm

Title: LPG fuel pressure correction
Post by: fivepoint6 on November 08, 2015, 09:01:32 pm
Hello,

anytrim can do fuel pressure correction based on differential pressure
(fuel pressure - map).
It seems that this only works with a special 7 bar pressure sensor.
Is there an calibration option to use any sensor ?

Regards,
Jan
Title: Re: LPG fuel pressure correction
Post by: MWfire on November 09, 2015, 08:43:25 am
i use that correction on my car with 3bar sensors. I connected booth sensor to differential opamp.
Title: Re: LPG fuel pressure correction
Post by: lost on November 09, 2015, 04:13:57 pm
Do you use this one from landi renzo rail? Or there is better option?
How to connect it to vems?
(http://grzegorzbmw328.strefa.pl/alb21120.JPG)
Title: Re: LPG fuel pressure correction
Post by: MWfire on November 11, 2015, 11:06:20 pm
I think i have sensor from lpg tech(two map sensors and one temp sensor).
Title: Re: LPG fuel pressure correction
Post by: lost on August 17, 2016, 06:44:11 pm
(http://i.imgur.com/L31FJ1m.png)

Here is pinout for lpgtech pts01 and stag ps-02, they are same except different resistance on temp sensor.

Pin #4 is second MAP sensor ,  maybe it can be used for altitude correction if you dont connect it to engine.

I suppose pin#2 LPG temp, (-40-125C) and pin#3 gas pressure (0-6,75bar) should be connected to anytrim inputs on vems (sensor outputs 0-5v signal)

Hope this pinout helps someone...
Title: Re: LPG fuel pressure correction
Post by: wersch on January 15, 2017, 05:54:58 pm
i use that correction on my car with 3bar sensors. I connected booth sensor to differential opamp.

This differential opamp, is it installed on the vems genboard?
If you can please give a little more info on it cause i´m very curious on this topic  :)
Title: Re: LPG fuel pressure correction
Post by: MWfire on January 15, 2017, 06:17:23 pm
Yes, on board is that amp.
http://www.vems.hu/files/genboardv3/v3.8/genboardv3.8_sch.pdf
check u13.
DIff input is on JP9
Title: Re: LPG fuel pressure correction
Post by: wersch on January 15, 2017, 06:30:55 pm
Thanx  :D

So i put the signal from 2 equal sensors on pin1 & 2 at JP9 and this must be soldered because normaly this amp is not in use?
Where do i pickup the output signal so i can have it back to a MCP3208 input?
Title: Re: LPG fuel pressure correction
Post by: MWfire on January 15, 2017, 06:54:20 pm
Thanx  :D

So i put the signal from 2 equal sensors on pin1 & 2 at JP9 and this must be soldered because normaly this amp is not in use?
Where do i pickup the output signal so i can have it back to a MCP3208 input?
Chip is on board. Output is connected do mcp ch0.
Title: Re: LPG fuel pressure correction
Post by: wersch on January 16, 2017, 07:33:05 pm
Thanx for that info!
Only problem then is that i need two 7bar sensors, one connected to map and one for Fuelpressure.
Title: Re: LPG fuel pressure correction
Post by: Kamuto on January 16, 2017, 08:50:44 pm
Thanx for that info!
Only problem then is that i need two 7bar sensors, one connected to map and one for Fuelpressure.
no you dont need :) one only :)
Title: Re: LPG fuel pressure correction
Post by: lost on April 03, 2017, 08:29:53 pm
I think i have sensor from lpg tech(two map sensors and one temp sensor).

So you have one lpg tech sensor and you connect lpg rail pressure and vacuum from that LPG sensor to op-amp input 1&2?
Title: Re: LPG fuel pressure correction
Post by: MWfire on April 03, 2017, 09:18:11 pm
To diff amp.
Title: Re: LPG fuel pressure correction
Post by: lost on April 03, 2017, 10:13:27 pm
To diff amp.

Thanks!
And lpg temp sensor is not used?
Title: Re: LPG fuel pressure correction
Post by: Kamuto on April 04, 2017, 10:09:00 am
To diff amp.

Thanks!
And lpg temp sensor is not used?
would use it in anytrim
Title: Re: LPG fuel pressure correction
Post by: lost on April 13, 2017, 09:22:44 am
KAMUTO / VEMS / MWFIRE , could you share few screen shoots of anytrim/diffamp input configuration for lpg temp / pressure from your config?
Title: Re: LPG fuel pressure correction
Post by: lost on July 09, 2017, 02:30:32 pm
I have connected pts-01 sensor(it has two same map sensor inside 0-4bar 0-5V (for vacuum and lpg pressure) to JP9 diff amp.

ADC analog CH0 is calculated value from diff amp and it works i would use it for lpg fuel trim later...

analog CH1 is value in volts for lpg pressure and its displayed ok

problem is:

analog CH2 reads 0.0V when disconnected, if i connect 1 Volt wire, it reads 0V

When analog CH1 is connected to  3volt from sensor#1  (reads ok) and then when  i connect 1 Volt from sensor#2 to CH2,  CH1 then jumps (reads) to 5V, if i switch wires, then it reads 0v.

Is there problem with internal pullup?

I have VEMS v3.5 it sholud be like 3.3(http://i.imgur.com/XDGouy6.png)


Youtube link:
https://youtu.be/r8hH_3in7sU (https://youtu.be/r8hH_3in7sU)
Title: Re: LPG fuel pressure correction
Post by: lost on July 12, 2017, 12:41:20 pm
Can anyoone help me out with CH2,  input?
Title: Re: LPG fuel pressure correction
Post by: lost on April 01, 2019, 09:55:00 pm
Time to resurrect this topic :)

I never figured it out, my genboard is v3.5 (top picture), should be same as v3.3 (bottom picture, schematic)

I have two 7bar map sensors outputs connected to JP9 one MAP  is on intake vacuum, second MAP is LPG fuel pressure on injector rail (marked yellow on top picture)

And i get this result:
https://www.youtube.com/watch?v=r8hH_3in7sU&feature=youtu.be (https://www.youtube.com/watch?v=r8hH_3in7sU&feature=youtu.be)

How to get it to work ?


(https://i.imgur.com/7Y0fG5p.jpg)
(https://i.imgur.com/nsNfLsc.jpg)
Title: Re: LPG fuel pressure correction
Post by: MWfire on April 02, 2019, 08:56:19 am
Did you change gain?
Title: Re: LPG fuel pressure correction
Post by: lost on April 02, 2019, 09:13:20 am
No, where to change it?


BTW, i wanted to contact you for dyno after sorting gremlins in car and wiering/sensors (old was wrecked-not by me), so i got another crap for 500€ and transfered  VEMS  and LPG in it) i was wondering if you moved out from country like everybody else, and today i read on alfa forum that you tuned 24v tb alfa :) so please PM your mobile number i lost it.

Its drivable on gas now , and on lpg i need injector settings for barracuda/hana injectors.
Title: Re: LPG fuel pressure correction
Post by: lost on April 02, 2019, 09:38:00 am
Plese note that ADC raw is strange, like in video when i connect second wire on JP2.
First i shows 2.2V on ch1, then i connect other input and it shows 0.44V on ch2, And ch1 goes from 2.2V to 5V ???


And i am using  v3.5, maybe something is different than on v3.8
Title: Re: LPG fuel pressure correction
Post by: lost on May 15, 2019, 07:45:12 pm
bump on topic...
Title: Re: LPG fuel pressure correction
Post by: lost on February 03, 2020, 08:10:46 pm
Can anyone help i want to connect two map sensors (same, on on lpg pressure hose, second on vacuum hose) to vems diff amp on vems v3.5.

It also has temp sensor for LPG