Dallas 80C550

[John Dammeyer]

Hi Nick,

I've struggled with this one too.   What I currently do is increase the pulse
width to a maximum value of 13ms for n seconds.  I determine this from a change
in throttle position (dTPS) where the amount of change above a minimum change is
multiplied by a gain factor and then added to the current pulse width.

If the TPS goes above a certain value like 75% then I just apply a richer
mixture (11:1).

The tests are done with a large multi-bladed fan on a 2.4:1 reduction belt drive
so the load on the engine varies with the fan speed.  From idle to WOT I get a
stumble that I haven't been able to get rid of yet.  From 3500RPM to WOT the
engine just quickly increases speed to 5100RPM.  The Fan loads the engine such
that the engines maximum speed is at the peak torque value which for a propellor
is just perfect.

Can you tell me how you are doing the timing for the sequential injection?  ie:
at idle where are you starting/ ending the injection pulse and where at max
power?  How are you determining RPM?  I'm using the 80C592 and 95% of the code
is in Tasking C.

Regards,

John


>Date: Sun, 31 Oct 1999 11:40:06 +1300
>From: "Nicholas Parker" <nrparker at xtra.co.nz>
>Subject: Re: DIY_EFI Digest V4 #611
>
>Hi List,
>
>I have written an ecu in assembler for 80c552, but I now have a Dallas
>80c550 (8x faster or so).  Its for a 4 cyl, two coil, sequential injection
>etc. I haven't implemented 'acceleration enrichment' yet.  Can somebody
>please give me some guidelines,  ie:  The car I designed the ecu  for is a
>supercharged Toyota MR2 mk1. so It kind of operates in both modes...that is
>both forced induction, and natural aspiration bue to an electromagnetic
>supercharger clutch, and a supercharger bypass.
>
>Thanks,  Nick Parker.
>