Paul,
You seem to be on top of the cheap fuel injection world so I'm
seeking your advice. Don and I are a couple other buddies are racing
a Lemons car-a 1988 Honda Prelude with some 275,000. The car is
mechanically pretty sound, but its engine management system is
failing, though it's hard to diagnose because it only happens when
the engine is warm form running for considerable time.
One alternative to trying to trouble-shoot the stock system is to fit
a complete aftermarket engine management system. We don't need
anything terribly sophisticated or elaborate. Our priorities are low
cost and ease of calibration. The existing system controls both the
fuel injection and the ignition timing so we need a system that can
do both, though I guess we could replace the distributor with one
from a carbureted Prelude and go with a fuel injection only
computer.
I've seen the Megasquirt I (fuel injection only) for around $235 on
eBay for the solder-it-yourself version. The Megasquirt 2 can be had
for around $290. Do you think these are good choices, or do you have
a different favorite, cheap engine management system?
Any advice is appreciated.
Csaba
All of them have a steep learning curve. Megasquirt included.
It is better to learn how to do it yourself then you totally
understand how it works. It actually takes less time
to learn how to program it then it does to get some of them
working.
We have screwed around with the Motec for two months
and that supposedly is the best EFI system in the world.
How it is doing something is proprietary and that causes
problems when you are trying to trouble shoot something later.
If you don't mind learning a little Basic programming I would use a
Maximite and
write my own EFI.
http://geoffg.net/maximite.html
http://circuitgizmos.com/gizmo-store/#!/CGCOLORMAX2-Color-Maximite-Retro-Computer/p/53819402/category=14171440
gizmo@thebackshed.com
It appears this company is having trouble so you might have to contact Geof
in Perth for another source for the assembled color Maximite in the US
or Oz.
Geoff Graham
<geoff@mmbasic.com>
This is the easiest system to program for any hard ware control.
The Maximite Basic language is designed for hardware control.
To give you an idea of the power of a $60 maximite
it has 32Gig logging memory.
The $3000 Motec M800 only has 1 meg.
This is a digital record of what your efi did. It can save the
mixture value and manifold pressure every 100 RPM from idle to redline.
for hours every time the RPM changes buy 100 or even 10 if you wish.
You can save the date every tenth of a second if you wish.
There is plenty of storage space on the 32gig SD card.
You can then pull the SD card out of the MM and read it
in your computer.
To get that amount of logging with a Motec you have
to buy their expensive LCD instrument panel called the ADL 3.
This is all there is to logging data.
OPEN "log.dat" FOR OUTPUT AS #1.
You do this at the start of the program.
Then when the RPM changes
you do this. You can also do this every tenth of a second
if you wish.
PRINT #1 , rpm,
PRINT #1, manpress,
PRINT #1, intaktemp
Thats it. You have logged all your data.
When you exit the program you
CLOSE #1
all this helps when you are making changes to the mixture map
or table.
Here is a preliminary code. ' means it is info.
'SETPIN pin, cfg [,target]
'Will configure the external I/O pin according to cfg :
'The original Maximite has 20 I/O pins numbered 1 to 20, the Color
Maximite adds
'another 20 I/O pins on the Arduino connector. These are labeled D0 to
D13 and A0
'to A5.
'0 Not configured or inactive
'1 Analog input (pins 1 to 10, A0 to A5)
'2 Digital input (all pins and 5V tolerant on pins 11 to 20)
'3 Frequency input
'4 Period input
'(pins 11 to 14)
'(pins 11 to 14)
'5 Counting input
'(pins 11 to 14)
'6 Interrupt on low to high input change (pins 1 to 20, D0 to D8) for target
'7 Interrupt on high to low input change (pins 1 to 20, D0 to D8) for target
'8 Digital output
'(all pins)
'9 Open collector digital output to 5V (pins 11 to 20, D0 to D13) In
this mode the
'function PIN() will also return the output value.
'The starting line number of the interrupt routine is specified in the
third 'parameter
' target . This mode also configures the pin As a digital input so the
value of the 'pin
'can always be retrieved using the function PIN().
'See also IRETURN to return from the interrupt.
'See also:
'IRETURN PORT P
Mode 1
'Mode 4
For n = 11 To 20
SetPin n, 9 'set pins 11 to 20 as open col 5 v output
Next n
Open "data.txt" For output As #1 'data file
SetPin 8, 6, 10 'pin 8 low to high int gosub line 10
SetPin 10, 1 'manifold press on pin 10
SetTick 1000,20
BakGnd:
manpre = Pin(10) 'A to D on pin 10. may need to be scaled
manpre2 = manpre * 10
'Print manpre
manpre3 = Int(manpre)
PWM 20,manpre3,manpre3 'pulse width on primary injectors
'''''''''''''''''''''''and secondary 20 times a second
GoTo BakGnd
10 RPM:
RPM = RPM + 1
IReturn
20 RPMRoutine:
RPM=RPM*30
Cls
Locate 30,30
Print "RPM = ";RPM
RPM = 0
Locate 30,60 'col 30 line 40
Print "Manifold pressure = ";manpre 'EFIS function
IReturn
Read this. I may have some PC boards you
can have for the injection transistor with heat sinks.
http://www.rotaryeng.net/simple-cheap-555.html
I like to use cheap video coax to the injector
as that wire is a major source of electrical noise.
You will get lots of help from me on everything.
We want to put the code in the public domain.
Much much easier to program than C which is used by the others
including mega squirt.
Paul Lamar
Here is a nice circuit board from Hong Kong but there must be some
part kits or assembled boards out there some where.
Paul Lamar
Here we go. This looks like the best bet.
http://www.altronics.com.au/p/k9555-maximite-colour-computer-kit/
Paul Lamar
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