Hi everybody,
I'm planning to drive my LPG low impedance injectors directly by the Vems ecu.
The impedance is about 2 Ohms.
I have installing the new "4 channel LOWZ extension" from the vems webstore,and my questions are:
Have I still need a serial resistor with the injectors when using this 4 channel extension?
Can I drive the petrol and LPG inectors with the same output,swapping only the 12V + supply?
any suggestions will be aprreciate....
With new hardware from the manufacturer I'd get a definate answer from them.
If you would be kind enough to share it here it would save them and future users time.
Cheers
Rob
Hi Rob,
In fact I've talk With Katalin(suppose he is Vems engineer?),he explain me that:
----- Low Z extension must be installed for all injector channels ** before the PWM-ing is enabled (PWM is disabled by default by PWM duty=100% and time=25.5msec).
Series injector NOT needed when PWM-ing. (when PWM-ing enabled, configured PWM duty is usually around 40-45% and PWM time=1.0msec).
** take care ... A-B-C-D if using the 4channel version http://shop.vems.hu/catalog/lowz-extension-channel-p-160.html -----
Rob,after having read this words have you some idea ???
My opinion is that I only have to wire the two banks of injectors the same way swapping only the power 12V +,and set the right value on Vems (I'm using two different map for each fuel type).
I suppose this "Extension" should works with all type of injectors just changing the PWM duty/time
At this time I can't say nothing more about that because I'm waiting for my ECU (it is back from Hungary....)
I would like to thanks Katalin again ,he is a very professional guy ;).
Thanks Rob for fast reply !!.
Regards,
Michele.
He's explaining that
1) You do not need a Serial Resistor
2)That before you do anything at all, you need to set up the PWM function by:
* Changing the PWM duty from 100% to something between 35% and 50%
* Time from 25.5msec to 1 to 1.5msec.
Do you think I have to keep 100% and 25.5 on the first Petrol map and go to 35%~50% / 1~1.5msec when switching to LPG fuel or just keep this last set up for both of type injectors(petrol and LPG) ?
Do you think the way i will wire my injectors will be good?
Michele.
I have also think to use the 8 output :
A,B,C,D for the lpg
E,F,G,H for petrol,
is not more logical???
I would use same outputs for both types of injectors, but with switchable configs an relay. So some INJ outputs still usable for IAC, turbo control or something else.
Low-Z board for sure can be used for high-Z. Just set up 100% DC in correspondent config.
Gints
look my site
http://www.vems.hu/wiki/index.php?page=MembersPage%2FDamirMuha%2FLPG
i'm using lpg wiht pwm flyback for 2.5years so far without problems.
I'm switching +12v to injectors. But with that solution you need to put diodes in series with all injectors.
Hi everybody,
I have wired my LOW-Z extention board for driving my LPG injectors and it work.
For sure I'm on the begining and it need fine tune.
Does anybody have some info about this injector specs:
BRC yellow injector
Serial N°:09SQ9920003G
It will be great to find the battery voltage compensation time,rampup,etc...
I have choose to work with the 8 injectors outputs and what's strange is that I need to swap the common +12v injector when swapping from petrol to LPG,I can't supply the all injectors because when I run in LPG mode it seems that the petrol injectors stay open and flood the engine.
All sugestions appreciated....
Michele.
Here is my openning time set up:
Inj opening time : 0 µs
Inj effect rampup :504 µs
Inj ram.volt.comp. :4080 µs
Inj Volt Comp. :704 µs
Injector PWM:
Inj. PWM DC :50.2%
Inj. PWM peak time: 1.2 ms
why the change to low imp.. i thought we had your car running good with your old injectors.
the siemens 80lb are more then enough then would need.. the 60's would probably do. (Both have great spray pattern, much better then bosch 440cc and are both HIGHz)
my setting with landi renzo white injectors(40kW per injector)
256us
152us
4080us
704us
30%
2.3ms
Calibrated in range 11-14.2V
I have 6 high-z injectors (siemens) and boost control, and two pin bosch IDLE valve with diode across.
So all 8 inj outputs are used.
If i install low-z 8 channel extension board from vems shop, would my high-z and idle/boost valve work?
I want do use config switch to switch between 1.3ohm LPG injectors and high-z siemens injectors.
Switch only +12v to injectors with relay??!?
Also is it maybe more simple to make my own "external PCB" than removing fets from top of vems to bottom and installing lowZ board on top of v.3.5 board?
Quote from: lost on October 26, 2015, 03:37:44 PM
I have 6 high-z injectors (siemens) and boost control, and two pin bosch IDLE valve with diode across.
So all 8 inj outputs are used.
If i install low-z 8 channel extension board from vems shop, would my high-z and idle/boost valve work?
I want do use config switch to switch between 1.3ohm LPG injectors and high-z siemens injectors.
Switch only +12v to injectors with relay??!?
Also is it maybe more simple to make my own "external PCB" than removing fets from top of vems to bottom and installing lowZ board on top of v.3.5 board?
yes they will work :)
Quote from: lost on October 26, 2015, 03:37:44 PM
I have 6 high-z injectors (siemens) and boost control, and two pin bosch IDLE valve with diode across.
So all 8 inj outputs are used.
If i install low-z 8 channel extension board from vems shop, would my high-z and idle/boost valve work?
I want do use config switch to switch between 1.3ohm LPG injectors and high-z siemens injectors.
Switch only +12v to injectors with relay??!?
Also is it maybe more simple to make my own "external PCB" than removing fets from top of vems to bottom and installing lowZ board on top of v.3.5 board?
if you switch +12 to injectors with rellay, you need to add one diode in +12V line to every injector.
Does VE fuel need to be changed after installing lowZ board and turning on PWM?
Quote from: lost on October 27, 2015, 03:43:29 PMDoes VE fuel needs to be changed after installing lowZ board and turning on PWM?
yes
(http://i.imgur.com/SzwnOMo.png)
Im not sure how flyback needs to be connected.
anyone done this to confirm?
both schematic are wrong.
On every + line on every injector you need to have diode.