Posted by marty on August 17, 1998 at 17:58:03:
'75 530i
No start...
..spark all the way to the plugs;
I have a signal to the fuel
injectors (when you crank the car,
the FI injectorplugs carry current
strong enough to light a test light);
The Fuel pump is working and I
have fuel to the fuel rail.
THE PROBLEM: The ECU is not getting the
information it needs to tell the fuel injectors to open
when they are supposed to open. Even though the FI
injectors are getting current, I don't think
it is the correct signal i.e., they
are not opening and closing, there is no noise
eminating from them one would associate with
an injector opening and closing);
THE ASSUMPTION (or Misapprehension)
I AM LABORING UNDER: The ECU makes its decisions
about when and how much to open the
fuel injectors based on the information
it gets from the components of the FI
system BEFORE the throttle body.
This includes the airflow meter, the
throttle position indicator, and the wire
that goes to the No. 1 PIN on the
ECU.
The wire that goes to the No. 1 pin
on the ECU USED to go to the negative side of
the coil. I am assuming this is the PRIMARY SOURCE
OF INFO to the ECU as far as what the
holy hell the engine is doing. Since the signal
going to the coil is not what it expects to
hear, according to MSD, I have moved this wire
to the WHITE WIRE from the MSD box, as well as
putting a diode in line to step down
the signal from the MSD box.
Help!
Please repsond to : maroach@ix.netcom.com
or, william@seniorsix.org