I have an 89 accord EXi. I am having problems with hot starts as well. And I have a TW sensor code (Code 6). I have tried the sensor and the resistance at various temperatures is right on target. I used a resistor to "trick" the ecu into thinking the engine was hot and cold. (I tried various resistances). I also tested the wire and found no problems. I have also gotten the trouble code right off a cold start before the engine even began to warm up. If I stop the engine and try to restart right away it will not start. The only thing I haven't tried, which seems important, is watching the voltage accross the sensor with an oscilloscope.
Basically my question is does this sound like the same problem to you ? (anyone)
I am running out of money as I continue to throw parts at this car.
Thanks
Originally Posted by
bob01721
Sometimes, though, the TW sensor (coolant temp sensor) dies, and they frequently die in a funny way on Hondas -- they die "cold."
What I mean is, they track the coolant temperature from cold to hot and they tell the ECU what's going on. I think they put out .5V for a cold engine. As the coolant temp rises, so does the voltage, until it hits around 4.5V, maybe 5V for a fully warmed-up engine. Not exactly sure of the voltages here. But then, for some strange reason, they "go cold," putting out around .5V again, even though the engine is really fully warmed up.
In normal driving, you won't notice the difference. But when you try to RE-START the car, the ECU sees START and COLD, and so it dumps all kinda fuel into the injectors (which it SHOULD, to start a cold engine). This'll flood out a hot engine, though, and so it won't start.
Once the engine (and TW sensor) cools off, everything's fine again. Until the sensor warms up and "goes cold." Then, the cycle starts all over again. You can watch it on a voltmeter.