WOW... NO fuel huh? Riddle me this... How is the Engine continuing to turn over with no fuel? Using his example of deceleration on a decline, with no positive actuation of the throttle.

If you say because the transmission is turning the engine as you stated before then I shall simply walk away from this conversation because there would be zero point in continuing.

I'm not picking on you but you gave completely inaccurate information to someone as though it were fact... just because popular mechanics sez so doesn't make it right. IN FACT I can't believe they let something as rediculously misleading as that article be published under their name. Shame on PM.

 

Car and Driver also says it.
When Coasting to a Stop, do Not Shift Into Neutral - Feature - Car and Driver

 

What I do know quite well is the design and function of the Lucas EFI's and a bit less about Gems. This means Disco's pre-99 and RRC's pre-96

I do not claim to know about the intricacies of Current modern EFI's and energy recovery systems like on many Hybrid braking systems. So having said that there may currently be an auto manufacturer out there with a system similar to what has been described in those two articles.

HOWEVER, since we are on the Rover Forum I will stick with Rover systems. And the original queston asked was about a 1990 RRC. At no time during normal operating conditions when the engine is turning and all systems are functioning properly does the 14cux stop supplying a signal to the injectors. As you say in Laymans terms "off" does not occur. Under certain (not all) conditions / gear selections and when the road speed of the vehicle is greater than the power supplied by the engine and greater than the torque required to cause forward motion the torque converter in the ZF (and most all trans.) goes into a state called "overrun" (not in the Diesel sense of the term). This is where the torque converter freewheels and has a reduced control over engine speed. There will be some engine braking but not as much as with a manual trans. For obvious reasons this is different with a R380 which would directly control engine speed since the clutch would be engaged. Again, in this case you will have reduced pulse-width signal to the injector but not a ZERO state.


So, upon deceleration, foot off throttle, tps senses closed throttle and MAF senses lower flow rate, i.e. higher manifold pressure, the ECM goes into idle mode which is not the same as zero pulse signal.

As I said there may be an automaker out there with a system which cuts fuel completely upon deceleration but in our world and for the purposes of this forum that is not the case.