OK, so here's the problem. In our vans and probably in other'80s cars as well, the ECU kicks into closed loop mode on the late side, as the O2 sensors are slow to get to operating temp. That's why on later models, car companies started incorporating O2 sensor heaters. What this does is give excellent (rich) running when cold, probably what the engineers were looking for when gas was cheap. But you get worse gas mileage this way. Probably a lot worse, depending on how much around-town driving you do. So here's what I'm thinking. Rather than install a heated 02 sensor to correct the problem, why not just supply voltage to the ECU in the correct amount to trick it into going into closed-loop mode? This could be done with a transformer, a toggle switch, and a few long pieces of wire. Start the van in open loop, drive for a few minutes, and instead of waiting for the ECU to decide it's time, toggle it into closed-loop as soon as it runs smoothly. I say this because, having installed one of Ken Lewis' monitoring devices for the O2 sensors, it's painfully obvious that I'm driving open-loop much of the time, and thereby wasting gas. Anybody done this? Heard of it being done? Any reasons it wouldn't work? |
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