Quote:
Originally Posted by ECONORAM
I have only seen the fuel flow on the MPGuino go to 0.0 when coasting down the steeper hill (@45 mph, in 5th gear). Reasearch continues....
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Your switch hasn't done anything for you. The 4.7L does have DFCO, as I have verified in my own truck driving with a hand-held code scanner installed. If you have the overhead console with the MPG meter when you see it hit 99mpg instant chances are you're in DFCO. It's just that the DFCO programming is as non-agressive as it can be. Mine takes nearly 2 seconds of 2000+ RPM with no throttle sustained before it cuts injectors. It's more of an engine-braking situation, which is easily attainable with my manual trans but might be a problem for an auto truck. I find it more efficient to coast in neutral or EOC unless the hill is steep enough to require engine braking to prevent acceleration or unless you have enough momentum going into the downhill that you need to scrub speed due to traffic, signals, etc.
What you propose wiring is nothing different than an engine kill switch, which should be more easily accomplished by intercepting the cam signal sensor wire and installing a NC momentary switch directly to break signal when the button is pressed. I've contemplated doing the same in my truck as I do EOC, but I'm not sure how well of an imitation at DFCO this will do without actually shutting down your engine. You might need to keep the cam sensor active so you can monitor engine RPM while cutting fuel in your case as your auto will not bump start your engine for you.
If you weren't interested in OD you could install one of the VERY early 3-speed Torqueflite that has dual fluid pumps, one on input and one on output shaft, for the purpose of bump starting.