Ford EEC-IV Ignition Module

[imonkare at bessel.tutech.fi]

> =20
> >Hi! Could someone help me with a Ford EEC-IV TFI ignition module of a=3D=
20
> >Ford Sierra (with HALL sensor and european ECU). I=3DB4ve built a contro=
l=3D20
> >unit of a Siemens SAB80C517 microcontroller and now I have some=3D20
> >difficulties in controlling the IM.
> >
> >I=3DB4ve come this far:
> >
> >output    -------         ------
> >of              |         |
> >HALL            |_________|
> >               /          \
> >              /      Start advance (say 12 deg BTDC)
> >     "Max" advancd
> >     (about 90 deg BTDC)
> >
> >"Start advance" is the point where EEC-IV fires when starting the engine=
.=3D
> >=3D20
> >Even if the ECU is disconnected the IM fires at "start advance" (limp=3D=
20
> >home). The ECU tells to the IM when to fire with a rising edge. I tried=
=3D20
> >that too. I switched the ignition signal OFF at "max advance" an ON when=
=3D20
> >I wanted to fire, I could fire only AFTER "start advance". When I had an=
=3D20
> >advance of about 30 deg the IM fired at "start advance".
> >
> >So, a few questions: Am I so far right?

=20
> From the way you've described your TFI unit functionality, my guess
> is that it's not a Ford TFI unit but a Ford EDIS unit. This takes
> in the 36-1 signal from the VRS sensor (not HALL) and converts it
> to a signal with 50% dutycycle and rising edges at 10 deg BTDC
> for each cylinder which it feeds through to the EEC-iv. In return
> the EEC-iv sends out a required spark advance signal every firing
> event where the width of the pulse sent relates to the spark
> advance required. The pulse timing from the ECU does NOT affect the
> ignition timing. After a certain number of firing events without
> receiving a valid advance pulse from the ECU, the EDIS switches to
> it's default spark advance which is 10 deg BTDC. The EDIS unit of
> course drives the standard Ford twin-coil pack (wasted spark).=20
>=20
>=20
> >Does ECU take care of dwell? With the falling edge? How to calculate tha=
t?
> >
>=20
> Dwell is handled automatically by the EDIS unit, but rate of
> change of spark advance must be limited by the ECU to a few degrees
> per firing event to avoid screwing it up.
=20
Brian,

I=B4m not sure about the name (TFI or EDIS), but it uses a HALL sensor for=
=20
sure. I have the system installed on my car and with EEC-IV ECU it works=20
fine.


Ilari Monkare, imonkare at bessel.tutech.fi