VEMS Community Forum
Technical => Fuel Injection => Topic started by: lost on July 31, 2015, 07:55:55 pm
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Does someone here runs LPG injectors directly from VEMS, i want to install hana 1.3ohm on low-z board.
Question is how to use LPG MAP and temperature sensor to measure gas pressure and set it up in vemstune.
And is it possible to switch from LPG to petron injector while engine is running if they are connected in parallel with each other and i switch +12 to them.
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Does someone here runs LPG injectors directly from VEMS, i want to install hana 1.3ohm on low-z board.
Question is how to use LPG MAP and temperature sensor to measure gas pressure and set it up in vemstune.
And is it possible to switch from LPG to petron injector while engine is running if they are connected in parallel with each other and i switch +12 to them.
I think there should be no problem at all with it, using some anytrim channels with lpg temp + lpg pressure for corrections, and dual maps with output which will switch injector feed relay from lpg to petrol injectors
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Hello Lost,
Running LPG and Gasoline injectors from the v3 and switching is the 12v (and map) when switching in between supported; I also have an application like this on my own car.
But there is one important requirement, you will have to fit diodes inline from each 12v to each of your injectors (example if 4 cyl -> you need 8 diodes) for both the gasoline as well as the lpg injectors to be able to switch the positive over without problems.
Best regards, Dave
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Hello Lost,
Running LPG and Gasoline injectors from the v3 and switching is the 12v (and map) when switching in between supported; I also have an application like this on my own car.
But there is one important requirement, you will have to fit diodes inline from each 12v to each of your injectors (example if 4 cyl -> you need 8 diodes) for both the gasoline as well as the lpg injectors to be able to switch the positive over without problems.
Best regards, Dave
What type of diode i need to use inline (series) for every injector with gasoline lpg?
30V transient diode
18V unidirectional transient diode
BY399 3A fast diode
I need to order from webshop...
Thanks!
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Hello Lost,
For LPG injectors you need: by600-5, fast diodes 5A. Not available in webshop, but DigiKey (or other like arrow, mouser) surely has them.
Make sure you order the double amount + some extra, example: if you have 8 cyl you (with 1 injector per cyl) you'll need minimum 16 diodes + some spares.
Best regards, Dave
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But there is one important requirement, you will have to fit diodes inline from each 12v to each of your injectors (example if 4 cyl -> you need 8 diodes) for both the gasoline as well as the lpg injectors to be able to switch the positive over without problems.
+1
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I have diodes, but what about flyback wire...
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(http://i.imgur.com/RZ8IMHg.png)
Kamuto suggested i connect both flyback and +12v to relay pin 30, and then switch both at the same time between two injector sets.
(If i connect flyback to both lpg and petrol injectors thet both sets would get +12 all the time over flyback wire...)
Can it be switched while engine is runnig?
Does anyone has setup like this one to confirm.
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I allready have config switch, if config#2 is for LPG could i use one output for relay that switches +12/flyback to LPG injectors?
So this relay would be active only when i switch config#2
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I allready have config switch, if config#2 is for LPG could i use one output for relay that switches +12/flyback to LPG injectors?
So this relay would be active only when i switch config#2
yep
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If i install low-Z extension inside vems for all 8ch, and remove existing TS diode from vems, connect flyback wire to extension board.
Would flyback and +12 be ok like this? Switching flyback and +injector supply when i switch to config2 and activate relay.
Does anyone has it set up like this ?
(http://i.imgur.com/RZ8IMHg.png)
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If i install low-Z extension inside vems for all 8ch, and remove existing TS diode from vems, connect flyback wire to extension board.
Would flyback and +12 be ok like this? Switching flyback and +injector supply when i switch to config2 and activate relay.
Does anyone has it set up like this ?
Hello Lost,
Yes i have a setup similar to the picture you posted on my daily driver, but i have flyback wire connected to switched vbatt (wire 15) not wire 30 to have all power to VEMS v3 off when ignition key is off.
Best regards, Dave
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(http://i.imgur.com/BT07Z24.png)
I have update drawing, now injector switching relay pin 30 (flyback and +12) is supplied via key-on ignition relay that supplyes vems e36-pin25. (turns on vems).
Could you check if its ok for injector switching relay to be controlled with VEMS output, and does this relay needs diode between pin 85 and 86?
Thank you Dave!
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I have update drawing, now injector switching relay pin 30 (flyback and +12) is supplied via key-on ignition relay that supplyes vems e36-pin25. (turns on vems).
Could you check if its ok for injector switching relay to be controlled with VEMS output, and does this relay needs diode between pin 85 and 86?
Yes, switching the relay from v3 is perfect, that's what i do on my car;
You can use the fuel pump output to switch the relay:
- in map A (gasoline): the fuelpump function switches the normal fuelpump relay.
- In map B (LPG): configure the fuelpump function to turn on the gas relay (this powers LPG injectors but also gas shutoff valve on pressure regulator). The fuelpump function has special handler that switches previous output off and new output on when difference in output configuration is detected between map A/B take care only fuelpump function output does this.
Best regards, Dave
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Second version, here lpg injectors are connected to low-z extension board flyback wire, and gas HIGH impedance injectors stays connected as before via 30v TS diode to vems board ec36 pin 12 (classic setup)
Could that work?
One config would be with PWM one without.
(http://i.imgur.com/ShH9Mao.jpg)
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no
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Got this from: http://www.vems.hu/wiki/index.php?page=MembersPage%2FDamirMuha%2FLPG (http://www.vems.hu/wiki/index.php?page=MembersPage%2FDamirMuha%2FLPG) (image was lost on imageshack)
Dont get it how flyback and vems inj out are connected between lpg and petrol injectors on this drawing?
And is zener 50v diodes for protection, thats missing on my drawing.
(http://i.imgur.com/s18hqOC.jpg)
vs
(http://i.imgur.com/BT07Z24h.png)
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I have update drawing, now injector switching relay pin 30 (flyback and +12) is supplied via key-on ignition relay that supplyes vems e36-pin25. (turns on vems).
Could you check if its ok for injector switching relay to be controlled with VEMS output, and does this relay needs diode between pin 85 and 86?
Yes, switching the relay from v3 is perfect, that's what i do on my car;
You can use the fuel pump output to switch the relay:
- in map A (gasoline): the fuelpump function switches the normal fuelpump relay.
- In map B (LPG): configure the fuelpump function to turn on the gas relay (this powers LPG injectors but also gas shutoff valve on pressure regulator). The fuelpump function has special handler that switches previous output off and new output on when difference in output configuration is detected between map A/B take care only fuelpump function output does this.
Best regards, Dave
That is great for LPG swithing.
What about:
(http://i.imgur.com/ZjOoHEg.png)
If left like this is switches from petrol to lpg for 2.88 seconds. And then switch back to gaseline, and then activate relay again and switch to LPG when cranking?
Do you use 0 seconds in this map?
I'm also intrested what settings for PWM on Gas and LPG injectors to use with extension board, i have barracuda (HANA) lpg injectors.
And most important thing, do you have LPG reducer valve + connected to relay pin 87 (LPG flyback wire) like on picture below and is diode needed on that lpg valve/coil.
Thanks.
(http://i.imgur.com/ApXdD4wh.png)
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Hello Lost,
If left like this is switches from petrol to lpg for 2.88 seconds. And then switch back to gasoline, and then activate relay again and switch to LPG when cranking?
Do you use 0 seconds in this map?
No, since the engine is not stopped on map switch A->B (or reversed) these settings do not activate, use normal settings
I'm also interested what settings for PWM on Gas and LPG injectors to use with extension board, i have barracuda (HANA) lpg injectors.
And most important thing, do you have LPG reducer valve + connected to relay pin 87 (LPG flyback wire) like on picture below and is diode needed on that lpg valve/coil.
Well that depend on your LPG injectors, i use Prins injectors if i remember correctly i use 3msec peak-time and 40% hold. Determine the settings for your LPG injectors when the engine is running, in this case lower is better for both (lowest setting for peak and hold, where injectors still open reliably; you can start from my settings).
Yes i connected the LPG shutoff valve to the switched LPG injector supply.
Best regards, Dave
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Thanks to everyone for help,
Car now starts , i had to double reqfuel- now 20ms and double VE map (90 at idle) values to get it to idle at lamda 1.
EGT is spiking at 300- 1000c at idle. depending on cycles.
I need to drill out nozzles from 1.5 to 2.4mm, hope it gets better then.
I have it connected like this:
(http://i.imgur.com/ApXdD4wl.png)
Is it possible to switch lpg/gas when engine is running?
Without burning fets (relay switching).
And is there any way to convert lpg injecor flow to cc that vems uses to calculate req_fuel.
I have six 130nL/min lpg injectors.
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Is there a way to determinate best PWM settings, if i cant see any change when chaning from 35 to 30% and 3 to 2ms.
Engine idles at 0.9 lambda if i lower VE then it dies, its on 900rpm...
What to look at? Is lambda different on LPG?
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Still need info how to determinate correct pwm settings for new low-z injectors.
I got high consumption , very high egt, 1200c on throttle, lambda is good on power but its always rich 0,85-0,9 on idle or engine stalls.
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Still need info how to determinate correct pwm settings for new low-z injectors.
I got high consumption , very high egt, 1200c on throttle, lambda is good on power but its always rich 0,85-0,9 on idle or engine stalls.
low timing maybe?
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Still need info how to determinate correct pwm settings for new low-z injectors.
I got high consumption , very high egt, 1200c on throttle, lambda is good on power but its always rich 0,85-0,9 on idle or engine stalls.
low timing maybe?
tried to add 10deg to timing with no change.
Could you help me how to calculate req_fuel for lpg injectors, they are 130 nL/min that would be 1300cc so it makes no sense to me now they have nozzles for around 35hp per injector.
I'm also not sure how to get correct PWM settings, it works with 15% it works with 35% , i dont see any change, it dies below 1.6ms and idles same with 1.6 or 3 ms.
I'l post log if i found upload/hosting site.
(http://i.imgur.com/R0NXV5O.jpg)
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Can anyone write short info on how to calculate reqfuel for LPG and how to setup PWM values for lowZ injectors.
Just a few pointers.