Some thoughts and questions on EFI

[cary_mccallister at hp-corvallis.om.hp.com]

______________________________ Reply Separator _________________________________
Subject: Re: Some thoughts and questions on EFI
Author:  Non-HP-Diy-Efi-Owner (Diy_Efi-Owner at coulomb.eng.ohio-state.edu) at 
HP-Corvallis,unix1
Date:    5/5/94 12:14 PM


     
> 02 sensors react relatively slow - maybe 10 readings a sec? 
> TPS - sensors - at least 10 readings a second if not more
> Temp sensors - 1 reading a second
> RPM sensor - at 10,000rpm (why not?) - that 600,000 degrees per second.  4 
> bumps on the crank shaft (ie - crank triggered ignition) would mean less 
> than 1000 per second...
> MAP or MAF sensor - 1 per second - maybe  more... 10?
     
For temp, intake air temp would also be good.
     
> The system would have to work at:
> Startup
> Idle
> part throotle cruise
> WOT
> anything else?
     
How about deceleration fuel cut.
     
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One thing I have noticed that has been missed so far is battery voltage.  
You need to measure this to correct the pulse width sent to the injector.  
Perhaps there are some new injector driver circuits out there that do this?

I have been using the MC 3334 form Motorola.  

My experiments so far are probably a little crude to what I have read.  I 
have been using a PC parallel port connected to a A/D converter and then 
used a lookup table to calculate the pulse width.  To date the system has 
idled the car, but fails to accelerate properly ( engine stumbles and dies 
).

Cary McCallister
cmcalstr at hpcvts.cv.hp.com