New to the list...

[Bruce Plecan]

Different Displacements?.
Different number of cylinders.
Your braver then I.
If your in the states might rethink and use just a hac'd gm ecm.
I'm not familiar with all the strategies inna Bosch but there's alot going
on in an oem ecm, and without knowing all the tables, settings, switches,
and actual code you might wind up quitting.  Just a matter of starting at
the beginning, rather then redesigning the wheel
Grumpy

----- Original Message -----
From: "TVS" <TKMVS at clara.net>
To: "DIY EFI" <DIY_EFI at lists.diy-efi.org>
Sent: Monday, June 12, 2000 7:06 PM
Subject: New to the list...


>     New to the list and could do with some advice regarding a EFI project!
>   I'm in the process of fitting, and modifying, a Bosch L Jetronic EFI to
a
> MG Midget. I've got most of the bits including the ECU from Jaguar XJ6.
>
> In order to recalibrate the system I'm planing on reading the analogue
> output from the airflow metre with a laptop PC. The PC will then use a
> lookup table for airflow and rpm to find a new value which will be
converted
> to analogue and sent to the ECU. I'm also going to fit a O2 sensor to
ether
> help me build up a map or run in  closed loop with the PC. Can anybody
tell
> me if I'm missing something important or got something fundamentally
wrong?!
>
> I've got a few more plans/questions:
> 1) The O2 sensor has 4 wires (From a Bosch Motronic I think) 2 white going
> to a red plug... power? and a grey and black... out put with black ground?
>
> 2) How many times persecond should the PC be able to read the data/look up
> value/output data? I was considering about > 10Hz if possible.
>
> 3) What sort of resolution should the look-up-table/map have? Again I
> reckoned on 0.1V from the airflow metre (2.5V to 7.5V I think) and 50rpm.
> RPM range from 500-7500rpm so giving me around 7000 values in a 140/50
> table?
>
> 4) If I have sufficient processor time left mapped ignition would be
nice...
> but I'm running out of ports on a laptop! (only one parallel port)
>
> 5) Oh, and perhaps most important... the ECU fires the injectors every 3rd
> ignition pulse as it from a 6 cylnd. engine. I need it to fire every 2nd.
> Can I modify the 'divide by 3' bit in the ECU or should I fit a sensor in
> the dizzy/on the crank to send 3 pulses per rev to it?
>
> 6) As the flap airflow metre looks like it's going to be quite a
restriction
> on the flow... I was wondering if I could use a hot wire meter from a JE
> system. Are these self contained units? i.e. do I just supply it with
power
> and it gives a voltage out like a flap meter? Or does the ECU from these
> systmes need to do some clever suff as well?!
>
> All advice other than 'Don't do it!' ( I have had that in the past ;-)
> gratefully received... Please excuse any spelling mistakes that make it
past
> the checker...Dyslexic :-(   Many thanks, Toby.
>
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