I know that in newer cars it is (ever so) slightly more efficient to coast in gear because fuel injection cuts off and the engine turns off of momentum only...thus saving the gas it takes to idle. Is this true for my 94 Formula as well?

 

i would have to say yes that coasting in gear the pcm does cut the injectors to save gas sometimes i can feel it kicking in again even atleast thats what i think i am feeling bu yes i do believe your car would do it too being as how our cars are the same year

 

Yeah, I definately hear and feel a little grumble when I start to give gas after coasting, which is what made me think that our cars have this feature. Thanks.

 

The pcm has a fuel cell cutoff. You tell it that above a certain rpm and speed if the throttle is closed it cuts fuel after a set period of time. Also you can set a map setting to turn on // off

Example: Mine above 1400 rpms and above 32mph if I close the throttle it will switch to decell mode in .1 seconds. (I am not a tuner, but believe this can affect the rich pop that many lt1s suffer from when you let off)

 

[QUOTE=jsetzer]The pcm has a fuel cell cutoff. You tell it that above a certain rpm and speed if the throttle is closed it cuts fuel after a set period of time. QUOTE]

I believe that is correct. I live in a hilly area of San Diego, and down one particular hill close to home, when I lift in 2nd, there will be some throttle held in by the PCM until a slower speed/RPM is reached, then the fuel is cut off, and you can really feel the compression and cubes holding you back. I believe this reduces the HC dump that is usually associated with a sudden throttle lift, and prevents the muffler from accumulating unburned gasses. I kind of miss the cackling and popping, though. FWIW, an '05 GTO will cackle pretty good upon deceleration in gear . . .