[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
Re: UrQ FTCU ground on the intake - What the #@$%.
# It might work, but then all your sensor returns would be thru
# the main engine block ground strap which is carrying the
# alternator output...
# One of the first things that Bellevue Motorsports did to my
# ex-UrQ was add another ground strap from the intake manifold
# to the body!
... excellent post Orin ... as usual! :)
I noticed that the '85 urQ has such a wire installed as well, as
did the newer GT Coupe. The ground wire is a moderate sized braid
that went from the right front of the valve cover to a spot on the
body right above the right headlamp. I've been meaning to do this
to my car as well.
FYI, I found a problem on my '83 urQ where the main ground braid
from the engine block to the body (on the left motor mount) had
nearly broken from motion/vibration over the years. If that con-
nection were compromised it might cause additional noise to be
coupled into the sensor signals.
Grounding is a big issue in automobiles today. I missed an IEEE
talk recently about this exact subject. On my urq the F/TCU is
not grounded to the frame of the car through its mounting as it
is mounted to the glovebox frame. This is what I would consider
to be the appropriate technique to minimize ground loops. My
recollection for the 5kCSQ is that there is a ground connection
of the frame of the ECU to the body.
I've picked up a copy of RDH's code disassembly so I could evalu-
ate the possibility of adding a PROM address comparator that would
latch on an LED if certain addresses were accessed. I need to
find out if there are unique addresses for the different shut down
detection mechanisms. If this would work you could have a light
that comes on when an overboost occurred or one of the other situa-
tions that causes the ECU to shut off the fuel pump.
San Jose, CA (USA)