EFI

[Christian Hack]

> 
> From: "Stefan Toftevall" <stefantoftevall at swipnet.se>
> Date: Tue, 27 Oct 1998 19:10:27 +0100
> Subject: EFI
> 
> Wonder if someone is modifying the Nissan ECCS-
> system?  It uses the HITACHI EFI system.
> As I haven't owned this car very long, I'm looking
> forward to modify it for better performance.
> But as they say, the japanese systems are complex...
> 
> STEFAN ---
> 

I am currently modifying what sounds like essentially the same system as you have.
HD6802 uP, a couple of largish custom chips? Sound like it? Mine's out
of an Australian Commodore which was optioned with a 3.0L Nissan
turbocharged inline six engine (RB30ET). I think a similar ECU was used
on the VG30xx engines (3.0L V6's). I have found zero info on the web though.
One guy on the list showed me where the ignition and fuel maps are.

I have the PROM disassembled and have found a lot of the maps but the main
problem is which map is dependant on which variable and what does a coolant
temp of 0x83 mean and things like that. One guy on the list showed me where 
the ignition and fuel maps are.

It appears that the first 256 bytes are RAM locations for current temp, battery
voltage etc and so far I have worked out what 2 or 3 are for and I'm not even sure of
that. That should give you idea how difficult it is. The 

I have designed and are in the process of building a BDM style interface which
maps itself into a memory space not used in the PROM. Basically it's a serial port.
I will write a BUFFALO style ROM monitor which should allow me to read and
write memory locations (obviously unable to change the PROM tho'). Once I
get this done I should at least be able to do this with the engine off and if there
is a enough processor time I might even be able to do it with the engine running.
That would be really cool. I might even be able to get some sort of real time display
going as well.

I already have a ZIF socket on the outside of the computer which allows me to easily 
change PROMs without unplugging and unscrewing everything. It also allows the computer
to be mount properly.

One day I might even do a web page with what I know. So far there is only one or
two other guys that I know of plus yourself playing with this version of engine computer.


Christian Hack
christianh at edmi.com.au
EDMI Pty Ltd
Ph : (07) 3888 3066
FAX : (07) 3888 3583