Question
There are a few pages in Wiki that describe fuel injector properties:
How would one go about to determine what the correct values are, for the most important parameters?
- injopen
- injocfuel
My plan would be to get an engine already running with a Genboard where I have simply copied these values from other configs - so I manage to get the engine to start, run and idle reasonably well.
Also, it depends on flyback besides injectors (but low voltage 2x0.7V flyback is standard anyway).
Emil used simple lowvoltage 2x0.7V diode flyback for 1600cc (!!!!) injectors (cyl displacement=2250cc/4), and could get the engine idle OK (not perfectly though) with just guessing, without sophisticated measurements ?
What would be a method to find these values, just by playing around with VE values and observing lambda and injector opening times?
The absolute nice way is to
- fire the injectors off-engine
- at the normal operation fuel pressure (FPR applied)
- at known freq with mst.. msp.. self-trigger
- with forced pulsewidth (mdp.. ?)
Suggested measurements:
- 600..1200 usec in 200 usec steps
- and upto 2400 usec in 400 usec steps,
Fire extinguishers at hand. No smoking, etc...
Q: Should injopen, injocfuel and other related parameters be set to specific values or does it suffice if they are given as additional information to the flow table created?
I don't understand teh question. I try to answer it, but please clarify.
- If injopen is not tuned properly, it can be compensated in VE table (low-kpa numbers will be higher or lower)
- some value must be set for all these config variables, of course; estimates are usually OK here, but random numbers are bad
- You put the measured flowrate table to wiki, and we help make parameters that approximate it well.
Status log
- Mar 5th, 2005
Another BWM owner needs a Genboard install. Visit MembersPage/MattiasSandgren/PeppesBmw to check it out. We have some trigger issues to work out.
- Feb 12th, 2005
Added a page about a BMW 728 that I'm helping to convert to VEMS/Genboard with help from all of you and MembersPage/EmilLarsson in particular. Visit MembersPage/MattiasSandgren/BmwSevenTwentyEight to check out the wiring issues.
- Jan 23rd, 2005
I added myself to the MembersPage to contribute to the project.
About me
I am the main site administrator of [Sävar Turbo Site] and I have in recent years become more and more interested in combustion engines and cars in general. I have a computer geek background but mechanics always intrigued me - not only electronic gadgets.
I have several cars but my two main projects are :
- BMW E30 325iX (1989) MembersPage/MattiasSandgren/BmwEthirtyIx
- Volvo 142DL (1972) MembersPage/MattiasSandgren/VolvoHundredFortyTwo
The Volvo is long term, my focus is currently on the BMW. I plan to replace the Motronic ECU of the 325iX completely.