Brushedpewter

Do maximas have an injection off feature on decelaration or any other time???
This is pertaining to Automatics.

nismology

iTrader: (8)

During deceleration/coasting the injectors don't fire any fuel.

Brushedpewter

so this is true for both manual and auto???
also what generations of maximas does this applies to, the injection off feature.

nismology

iTrader: (8)

Yes this applies to autos. If i'm not mistaken this has been a feature of EFI since it's been around.

Brushedpewter

does the injector feature applies to certain speeds, certain conditions, certain elevation???

nismology

iTrader: (8)

1. It's not an "injector feature". It's a function of the ECM.

2. When coasting with the throttle completely closed the injectors don't fire until a little over idle RPM. They then begin firing to maintain idle speed.

Brushedpewter

can you tell me the precise rpm they start firing again?

IceY2K1

iTrader: (3)

The injectors still fire...just at a low pulsewidth.

A quick look at an old log shows ~2ms duration/~10% duty cycle with TPS = 0%.

kcryan

iTrader: (1)

Good u guys had me scared there for a seccond cause no gas is usually not a good idea

nismology

iTrader: (8)

What's wrong with no gas? Anyway i got my info from the FSM which distinctly said there was a fuel cut while coasting. Guess it's wrong...


I also noticed that coasting, whether the ignition was on or off, produced the same EXACT exhaust tone. I had a pretty loud exhaust so i could hear it clearly. This leads me to believe there is no combustion occuring while coasting.

Another thing to consider is that while coasting the ignition timing is at TDC itself. Zero advance...

Brushedpewter

my manual said the same thing. that fuel is cut off on deceleration and high engine rpm.