That's something I've always wanted to do too. I just couldn't imagine
trying to find the time to do it though. I would say the project would be
best done by at least 3 types of people. Software geek to write code.
(Me) Electronics geek to interface sensors to the computer. And the
mechanical genius / grease monkey that knows how an engine should work
mechanically, and can determine what the computer should be doing.
I would also think that the Gen 2 daks would be the best for this. OBD
2/3? would be much more work to keep track of. Would still be feasible,
but I would think that we would need the basics down first.
Sounds like a project I need to retire before I have enough time to work
on.
BTW back in the college days the microcontroller we used was the Motorolla
68HC11 which was quite common as an engine controller. I always wanted to
go and update it with the faster big brother 32 bit system so that it could
sample data more frequently and have a little more intelligence to it. I
think it would be great if the computer could adjust itself for driving
conditions on the fly. Ideal toy would be dual fuel tanks / pumps /
injectors with different octane gas in it. The computer can adjust timing
fuel as needed to use low octane gas when at highway cruising speeds, but
when the go pedal either makes a sudden change, or goes more that 3/4 of
the down it can start dumping in the high octane fuel and messing with
timing so that you can fly! Best of both worlds economy & power. Ok,
enough rambling...
David Henry '94 CC 4x4 318 5Spd in MI
> Date: Tue, 23 Feb 1999 01:50:22 -0500
> From: Jon Steiger <stei0302@cs.fredonia.edu>
> Subject: RE: DML: R/T SBEC (Computer) Rag session
>
> I'd like to try to make a new computer some day... I've got the
equipment
> to burn microcontrollers and a C compiler that generates code for
Microchip's
> line of microcontrollers. So, we've got the tools, all it would take is
> getting the right code on the chip(s) and wiring the thing up...
>
> I don't know anything about how CC did the Dak computers, but I'm
assuming
> they're using code protection, which makes reverse engineering extremely
> difficult. You can't just pull the code off the chip, so (as far as I
know)
> what you have to do is follow all the leads to see what sensors they're
going
> to, then find the specs on the sensors (voltage range), and apply varying
> voltages to that pin while monitoring all of the others. You *might* be
> able to extrapolate the way the computer is thinking by doing that. (I
don't
> have any formal training in this area, so I could be completely off the
> wall; the above is how I'd do it though.) Anyway, a time consuming,
difficult,
> expensive process.
>
> Anyway, Accel sells a fuel injection kit that you can use to install
> fuel injection on any vehicle, and the general theories about EFI are
> available (the diy_efi mailing list is an example), so it seems almost
> like it would be easier to start from scratch. Use the pre-existing
> sensors and injectors to get a fuel injection system up and running,
> then add all the other stuff. You could probably run the custom computer
> in tandem with the PCM, with the custom computer intercepting all signals
> to and from the PCM. Anything that hasn't been implemented by the custom
> unit could be "passed through" so the PCM won't generate an error code
> for a sensor it doesn't see... One problem with this method is the
OBD-II
> tests. The PCM will sometimes purposely run the engine lean or rich to
> test the O2 sensors, so if the PCM sprays extra fuel and the engine
> doesn't go rich, it'll probably cry "foul". One way around that might be
> to build an "engine simulator", which would be a computer that interfaces
> with the PCM, and feeds it sensor signals to simulate a properly working
> vehicle. Problem with that is if you know enough to do that, you can
> probably build an entirely new PCM anyway... :-P
>
> On the pre-'97 trucks, the guages and stuff aren't run by the computer,
> so starting from scratch would probably be fairly simple; you just need
> to get the fuel injection up and running, then add a few other little
> things. I have a feeling it'd be a lot harder on the new trucks.
>
> Once I swap out my 318 for a 360, I've been thinking of putting the
> 318 on an engine stand and using it to develop a computer. The problem
> with this though is that I barely have time to do the simple piddly
> little mods that I want to do to my Dak, let alone tackle a project
> of this magnatude!
>
> If anyone wants to collaberate on such a project though, I might
> be interested in participating, even if its just to butt in with
> my opinions... :-)
>
>
> -Jon-
>
> .--- stei0302@cs.fredonia.edu ------------------------------------.
> | Affiliations: DoD, EAA, MP Race Team, NMA, SPA, USUA. RP-SEL |
> | '96 Dodge Dakota v8 SLT CC (14.58@93.55), '96 Kolb FireFly 447 |
> `----------------------- http://www.cs.fredonia.edu/~stei0302/ ---'
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