"
The bit of info that might interest
you is to do with apparent cold start probs with the FJ. I wired my ECU
in with several relays switched via the various power lines from the ign
switch. Eg. ECU and injectors have separate
relays/fuses. Starter circuit comes off the 'start' for the
starter motor etc. ECU and injectors relay is switched by the 'run'
position on the ign switch. All power goes to the relays from the
battery via a fusable link.
The problem I was having was when
the motor was cold, it would fire and run for a couple of seconds, then
die. This would happen two or three times, sometimes more, on a cold
morning before it would run properly. I found several problems
:-
1. coolant temperature sensor
had shoddy connections. Made a big difference to idle
speed.
2. Throttle position switch
was intermittent. Sometimes it would indicate closed when the
throttle was closed, and other times not. Opening the switch and
adjusting the contacts fixed that. Driveablility was poor, as well as
starting.
3. This was the
tricky one to find. As you know, the 'run' circuit supplies power during
running and starting of the motor. 'Start' only supplies power when
starting. After hunting, I found that when turning the ignition switch between
'run' and 'start', there was a short, but momentary point between
the two positions where the 'run' circuit has no continuity. This
was confirmed when switching between run and start, the power relays for the
ecu would click off for a split second. So what I did was
put a 2200mfd 25volt capacitor across the coil of the ECU relay, and
an isolating diode in line with it. In effect, the capacitor is
smoothing the power supply to the relay in
between the brief interuption caused by the switch
contacts. The relay thus does not turn off, continuing to supply
power to the ECU during the whole start process, instead of a flickering
on-off unstable power supply. I now have a motor that starts first time,
every time, without missing a beat, that idles about 1200 until warm, then
700-750 rpms at normal temps with a stock ECU.
"
