Hi Bob and all people here,
As I suspect that the ECT sensor could go bad. From the always run rich with black smoke, choking and backfire... I have an idea of not using the ECT sensor.
But I will use the variable resister instead. Then I can adjust the voltage signal feed to ECU directly with my adjustment. I will put a variable resistor with a knob into the instrument panel, wired into ECU connector pins directly. And then I can set virtual engine temp signal as prefer.
So...if it working...
I can adjust the fuel volume as I like...However I think varying fuel rate approx 20 % should be OK to avoid too rich or too lean combustion.

Could my Idea will worked...?
Just my strange idea.
I intend to save the cost of ECT sensor and buy VR instead.

Set rich to cold start and set middle-lean to hot long run to save fuel in the final approach.

Daeng
Thailand

Other idea is that.
If I could adjust the single time injection of the fuel per cycle to the sequential would be better..?
Mean that each injector will fire the fuel in the different sequential time while my B230F injector alway fire in the same time.
Does it possible to do..?
I intend to improve fuel consumption and power output also.

Daeng

From the FAQ section
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According to Chilton's (you may choose to disregard this):
"The coolant temperature signal to the control unit has a great influence on the computed injection period... For example, when the engine is being started and is cold, the amount of injected fuel must be relatively large.
"If the control unit receives a signal higher than 302F (150C) or lower than -40F (-40C), it will interpret the signal as a fault...the control unit will assume a substitute value corresponding to 32F (0C) on starting and 68F (20C) when the engine has started.

"With the control unit connected, connect a voltmeter across LH ECU terminals 13 and 5 (ground), turn the ignition switch ON.

At 68F (20C) the voltage should be 2.0 +/-.5v volts.
At 104F(40C) the voltage should be 1.2 +/- .3volts
At 176F (80C) the voltage should be .5 +/- .2volts.
The resistance values between pins 13 and 5 or between pins on the sensor are (by eye from the chart):
32F (0C)-- about 6000 ohms within a range of +/- 10%
68F(20C) -- about 2300 ohms "
104F(40C) -- about 1300 ohms "
140F(60C) -- about 600 ohms "
176F(80C) -- about 300 ohms "
212F -- about 190 ohms "
[Response 2: Steve Ringlee] ECT resistance "cold" should be around 6k ohms at 32 degrees F (0 deg C), 2300 at 68 degrees F (20 C), and 200 at 212 F (100 C). However, try checking your ECT wiring: Between pins 13 and 5 at the LH ECU (with sensor DISconnected) resistance should be infinite. Voltage with the ignition ON and sensor connected, measured between pins 13 and 5, should be:
0 C=around 3 volts +/-.5v
20C=around 2 volts +/- .5v
100C=around .3 volt +/- .1v
If these aren't correct, check the connections in the ECT wiring harness. Check engine ground connections at the intake manifold. If the voltage is zero, your ECU is at fault
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Anyone could suggest me how to calculate the suitable range of variable resister to simulate the working resistance of ECT sensor..?


Daeng
Thailand

93-940 B230F 266,000 KM.