Why does my car consume fuel even when coasting (09 Accord I4 automatic)

[roosterk0031]

Originally Posted by ECONORAM

I don't follow. Both of my vehicles are automatics and have DFCO. The RAM only uses it for decel with a load--it is hard to get it to kick in with an empty truck. It will upshift a gear, relock the converter, and then cutoff fuel flow. I've watched it several times on the MPGuino.
The Avenger does DFCO in OD lock anytime you slow down from 63+mph...to about 55mph. Engine RPMs still happen, accessories still run for both vehicles.

I agree, learning how to NOT use the brakes so much is the best method.

I should say with my auto car's DFCO doesn't work where I live.

With the Stratus DFCO will only kick in if I downshift out of OD, I get heavy engine braking (should have started a coast sooner), must N coast as it won't coast very far in gear, and in gear it will downshift while coasting to slow even faster.

Impala and Malibu auto's they unlock the tranny when coasting so only way to get engine braking is to slip them into D, very little difference between Neutral coast and OD coast. Only useful if the hill is so big if I want the engine braking to limit maximum speed.

With the Cobalt engine rpm needs to be over 2,000 rpm (55 mph in 5th) so to get it to work on down hills I need to downshift, but the car goes open loop for a few seconds and consumption goes up to .5 gph, before going to 0. But as soon as rpm goes under 2k, back to 0.3 gph.

Area's with longer steeper hills, and some cars the DFCO to much lower RPM's than mine might be able to take more advantage of it.

[PaleMelanesian]

Back to the OP's vehicle, an 09 Accord. Most hondas (including my personal 96, 04 and 09) will do DFCO in gear above 1200 rpm. That's all that's required. If your gauge isn't showing it as such, you probably need to calibrate it to match the Open/Closed Loop status.

[Xist]

I asked about DFCO on SubaruForester.org and still have not received any responses, but there were mentions of the RPMs needing to be above 1800\at 1900, which is pretty heavy engine braking. They said that fuel gauges did not recognize DFCO and since they do not recognize lean burn, that makes sense.

As long as the engine is moving, it is drawing in air, right, which is all that is communicated via OBD-II, not fuel consumption?

The guy that said that fuel gauges did not show DFCO said to watch the temperature, it will go down, but except for big hills, I cannot imagine this ever happening, and it seems that when users notice it working, it only does a partial job.

[gone-ot]

ANALOGY -- Why do you BREATHE when you're asleep, you're not working?

[UltArc]

Originally Posted by Old Tele man

ANALOGY -- Why do you BREATHE when you're asleep, you're not working?

Although ones temperature does drop...

[mechman600]

My wife's Toyota Matrix automatic DFCOs all the time - any decel above 1500 in any gear. I can tell on the SGII because:
"LHK" (L/100 km) goes to zero.
"LOD" (percent load) goes from 16-18 down to 8-10.
"LPH" (Liters per hour) goes to zero
"LOOP" goes to "OPEN"
Etc.
If I am in the mood for DFCO, I shift down manually while decelerating to keep the revs above 1500.

[Xist]

Originally Posted by Old Tele man

ANALOGY -- Why do you BREATHE when you're asleep, you're not working?

I usually do not work when I am awake, either.

[PaleMelanesian]

Smart gauges like the Scangauge can figure out when DFCO is happening by looking at the throttle position (calibrated with the Cutoff setting) and Open Loop status.

[Xist]

Originally Posted by PaleMelanesian

Smart gauges like the Scangauge can figure out when DFCO is happening by looking at the throttle position (calibrated with the Cutoff setting) and Open Loop status.

Something else to calibrate? I still have not figured out how to calibrate the fuel. Each time that I fill up [and remember] I go to do that and it says "Full tank!"

No no no no no no no no no!

I need to print out those instructions again.

As I mentioned before, possibly in another thread, when I descended into a canyon in-gear, and then downshifted to third, it said that I was using 0.5 Gph, and if it did not enter DFCO then, I do not have any idea when it would, nor what I could do about it, besides installing a kill switch just for the canyon, to use while in drive, and everyone will tell me that is a bad idea.

[Xist]

Originally Posted by SentraSE-R

Xist, I found your post at subaruforester.org. You and jayliu1984 need to set up your devices (Ultra-gauges or Scangauges) to recognize DFCO. The UG EM v. 1.2 Injector Cutoff setup procedure is on page 50 of the Owners Manual.

MENU  UltraGauge Setup ..  Injector Cutoff

The SGII v. 6.0 fuel cutoff setup procedure is on page 16 of that Owners Manual.

Once you get your UG or SGII set up to recognize DFCO fuel cutoff correctly, you'll start seeing 0 fuel consumption, or 9999 mpg.

If you rely on a mfr OEM fuel consumption display (as I suspect jazyliu1984 may be doing), you're likely SOL.

Sorry, this is an old post, but somehow I missed it, and then happened to see it again recently. Thanks for pointing this out to me!