scangauge 2 owners please help! Fuel cutoff question.

I got my scangauge a few days ago and am getting very high mpg readings like 60- 9999mpg. In the manual it says to adjust the fuel cutoff so it is about 4pts above your TPS reading at no throttle. My TPS is at 15 while off the throttle so I set the cutoff to 19. Still same problem. The mpg while on the throttle seems about right but when I let off the gas it slowly climbs to 9999.
What did you guys set your cutoff to? Any other tips would be appreciated. Thanks!

What are some good x guages that you guys use.

 

The 9999 reflects when the fuel injectors shutoff during decelleration, I think what you're seeing is normal, although I can't fully tell from the description.

FYI, I left my SG at the default settings and once the fuel fillups were adjusted, the tank mpg's are always within a few tenths. The instantaneous mpg readings are always all over the map, I usually only use that to see mpg's when at a steady state.

 

9999 means injectors off. and you need tocalibrate it so the inst mpg are a little more accurate. befor min was calibrated i was getting 25mpg supposedly now it reads 15-19 mpg which is correct....i didnt really calibrate it the way the book tells yu cause i cant really keep filling up when i still have a quater tank left like the book tells you todo..my tps is not zero either but that has never messed ith them mpg..

 

Ok thanks guys. As far as I can tell I have calibrated it correctly. But.. I haven't filled up a second time yet so maybe thats also a factor. I will wait until I filled again and re calibrate it and seeif that helps.

 

oh ya on first fillup it reads like 30mpg or at leasr mine did

 

Oh ok ill just wait till I fuel up again. I love my scangauge already tranny temp is awesome! And a ton of other cool features.
What x gauges does everyone have/use? Any cool ones.

 

Not necessarily. It can also be an improper setting for the Fuel Cutoff function.

For what it's worth, I have an Aeroforce gauge which measures and can display the Injector Pulse Width. Injector Pulse Width is the amount of time in a 20ms period that the injectors are open (aka pumping fuel).

According to the gauge, my injectors never turn off. The only time it indicates 0.0 is when the engine is off. If I'm coasting in gear down the freeway, the injector pulse width indicates 1.9-2.0 ms so the injectors are still pumping gas 9.5%-10% of the time. When I coast in Neutral, the injectors indicate 2.0-2.1ms.

Mine is a manual so I don't know if the logic for the ECU is the same or not.
If someone could set their Fuel Cutoff setting to 0, I'd be interested in seeing what it indicates at 0 throttle coasting in neutral vs coasting in gear.