----- Original Message -----
From: Dan Carrington <dc_grafx@microworks.net>
To: Scott Pontius <spontius@worldnet.att.net>
Sent: Monday, January 01, 2001 9:14 AM
Subject: Re: 5-speed gearbox series E help needed (LONG)
>
> You mentioned you are having troubles with your FI. What troubles? It
sounds
> like you have had the car running and all. Did you have any troubles or
hints
> as to starting the FI for the first time?
>
> Thanks again
> Dan
>
The problem with my FI is the wiring harness. It is 20 years old, and has
been heated up sitting on top of that aluminum V8 so many times that it has
become very brittle. I found several broken wires while rewrapping the
harness, then during initial startup of the car it was only running on 6
cylinders. That was tracked down to broken wires in the leads to two
injectors. While checking the system, the leads to the thermotime switch
and the coolant temp switch fell apart in my hand. Then the car died again
a month later, that was finally traced to a broken wire at the connector to
the ECU. The wiring to the throttle pot has an intermittent fault somewhere
that I haven't found yet, and vibration causes it to open close
occasionally, this causes the ECU to cycle the injectors in accelerator pump
mode and causes an occasional stumble from the engine.
Now I have a new problem that has me stumped. I installed a new set of
injectors in preparation for the battle with the CA smog referee. On
restart, the car is running filthy rich, coughing black exhaust, won't idle
at all, won't keep running without about 1/4 throttle. I have checked just
about everything, no faults in the ignition, fuel pressure correct, pulled
all of the injectors incl cold start to check spray pattern and leaks,
swapped ECUs, nothing helps. It was so sudden, I just pulled the plenum,
put in new injectors, put the plenum back on and fired it up.
My theory now is that during the work, just by handling the wiring harness
to lay it out of the way etc, another wire has broken inside the harness.
Loss of signal from one of the sensors or the airflow meter would make it
run like crap if at all. The problem is that it's darn hard to track down a
bad/intermittent wire inside of a wiring harness.
I need a new wiring harness for the FI, but I haven't been able to find one.
VB has one for the TR8, but all of the leads are in the wrong places as the
TR8 FI is backwards from the SD1 version. I would make a new harness from
scratch if I could find a source for all of the correct connectors and color
coded wire. Worst case, I could buy the TR8 harness and at least have a set
of new connectors, and have to redo the wires.
Any ideas?
Scott Pontius
'78 MGB V8
San Diego
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