hello forum. i am in the procces, of converting my car , from carbiratur, to Fuel injection , and i plan to DIY an ECU.
my car, is a 1992 Audi 80. (1.6 lt). it seems, that it has no, crank position sens
or.
the only signal, relevant to my rpm, that i can get, is from the distributor. the distributor has a plug with 3 connections. +,-,sig. the sig connector goes from +12v to GND, So it is a hall effect sensor.

the thing is this : how is this signal, associated with my crank exact position??? or what is the case on most cars anyway?
(does it produce the signal once per 720degrees? or 360 ? )

thanks!!

If you remove the distributor cap and rotor arm, is there a thing that looks like an upturned aerosol can lid with windows cut out of it? If it does then you do indeed have a hall effect distributor.
Can you run a fuel injection system from it? No
A fuel injection system needs to know more precisely, exactly where in it's rotation cycle it is and it also needs to know top dead centre as the distributor runs at half the speed as the engine so it couls be 180 degrees out otherwise. A workaround could be to modify a 1990's Honda distributor to fit as it contains all three pickups and is very easy to wire up having three seperate plugs too. If not then you will need to make up a segmented "chopper" to fit on the crankshaft.
You could consider using K Jetronic which is a mechanical fuel injection system and would probably have been fitted to Audi 80's with more sporty engines than yours. This would require very little wiring or indeed knowledge and is a suprisingly good even by modern standards. :thumbup:

but if you know the degrees before TDC that the distributor signaled, and you know your RPM, then you can calculate the exact position of the crankshaft,after X time... why wouldn't this work?? cause in all the pdfs i have read, it mentions "injection from distributor" ...

(Also, i am planing to use the injection parts, taken from an audi 80, wich had injection)

Your distributor has two lots of TDC across four spark signaling points and you have to remember the crankshaft gets to tdc twice for everytime the camshaft gets to its "tdc position". What I am saying is that you would need to modify you distributor to get a useable signal for an ecu and the Honda distributor does this already. I also think you may well have a vacuum and mechanical ignition advance system fitted which will complicate things further. Ican't think of any mainstream fuel injection system that would run using just one signal pulse per rotation and I very much doubt a standard Audi one would.
This might help a little http://www.diyautotune.com/tech_articles/trigger_wheels_index.htm

If you wanted to go to the expense of an aftermarket system you could probably run it off a distributor but I doubt that would be cost effective on an older car. Do you know what system you have in mind?

If the injection system you want to fit looks like this http://www.spannerhead.com/2012/01/30/atomizing-fuel-continuous-injection/ it would be very easy to install. K Jetronic :)

There are many different after-market FI systems that you can use with that dist like SPITSTRONIC for instance where one can do fueling only and change ignition divide and so on----actually very popular in my country :thumbup:

as i sed before, i will use the FI from an newer audi 80, DESIGNED for my engine....
my ignition is ECU Controled... i have an ECU and everything... (And also the ignition coil is a 3 wire one)
1)i am not arguing that the honda distributor would solve much problems, i just dont seem to get why distributor is not good enough.
(maybe if you explain me, how Exactly the distributor work??)
2)if just one signal is not enough, then how does the Ignition system manage to do it??
3) i still cant get, why mathematically , you cant know the position of the crankshaft, by just one pulse....
Newton spend ALLOT of time, trying to prove that, if you know the position and the speed of an object, then you can know exactly where it will be And when :P after the second pulse, you can know your RPM, so.... what am i missing???

anyway, appart from what my distributor actually does, if i mount one toothed wheel like the one you posted, and fit it, so i know the exact position of the camshaft, inside its cycle, then this would be enough???

maybe my distributor, gives the cam position signal??
in that case, why do i need the crank position?? it will just require, that the engine makes a full rotation before it starts, correct??

Hang on, your distributor is ecu controlled? If it is ecu controlled then there is probably all the gubbins you need on the car already, I take it your distributor has no vacuum capsule on it then? Does it have an ECU up by the wiper linkage? Could you post a pic showing your distributor and maybe a pic of the fuel injection you wish to fit? I'm wondering if i'm thinking about your car having an newer set up than I thought it did?
Is your car B3 or B4 shape? I take it you don't have single point injection fitted then?