How to get the infinite MPG without EOCing in a 2000 Caravan?
 

I'm aware that I can make the van shut off the fuel injectors when the van is going fast enough (Such as down a steep hill going 35 MPH or faster) and I stick the transmission in Low. How can I make the injectors shut off at a red light, For instance? All that sitting uses up a lot of gas, Otherwise. I tried pulling the fuel injector fuse out with the van on but when I put the fuse back in the injectors didn't turn on again until I turned key off then on, So a fuse kill-switch doesn't work in this case.

The van is the 3-Litre model.

Also, What happens when I see the infinite MPG figure? Are the injectors off then?

Shut the engine off at red lights.

I'm asking how to do this without shutting the engine off. Can I switch the fuel pump on and off electrically?

If you turn the fuel pump or injectors off, the engine will die. That is what I was implying. Easier to just use the key or install a kill switch.

i'd go look for a factory service manual.

Thanks. I'm seeking a way to have the "9999 MPG" figure show up on the ScanGauge II (With the fuel not going into the engine) without shutting the car off and while keeping it in Drive, While also keeping the engine in good running shape.

I do have a copy of this:

http://www.haynes.com/images/product...30011cover.jpg

Well I don't think there is really a way to do what you want other than killing the engine but you could shift into park and you might use slightly less gas than while in drive. Alternatively you could have your RPM at idle adjusted as low as possible which would use the least amount of gas but it would be a ton easier and cheaper to just turn the car off

To be specific, I'm asking "How can I put it in fuel-cutoff mode without it being in deceleration fuel-cutoff mode at a red light?"

But the problem is if you cut off fuel to the engine it dies, as in it turns off.

It stays on in deceleration fuel-cutoff mode in low gear.

It may be in deceleration mode but the engine is actually off.

Hence fuel cut-off , it is what it implies , it does not limit the fuel it shuts it off.

The engine now turns by the road wheels force on the drive train.

Your ears think its running but its not
your free wheeling at that point.

That's because the engine is being run with the wheels (google it if you don't believe me) because they are turning while the car is still moving when you stop though and you cut off the fuel nothing is keeping the engine going. You can't get something from nothing. Like I said in my previous post there isn't a way to what you want to do.

So what happens if I pull the Engine fuse while the van is idling? Does it turn back on if I put it back in? Can I turn it off and on with a switch in this way?

Isn't this a kill switch?

So you'll get out of your car pop the hood and pull the engine fuse then wait for the light to turn green put the fuse back close the hood get back in the car and then go. But you won't just turn the car off???????????:confused::confused::confused:
:confused:

To induce fuel cut off without decelerating using neutral or the clutch will cause the engine to stop turning completely until the clutch is released, which is good.

What you can do to induce fuel cut off is a) put the trans in neutral or clutch in b) turn the engine 1 notch down toward off , this will stop the motor, then put the ignition back up 1 notch to the run/on position in preparation for putting it back in gear when the coast is near over c) release the clutch when ready to drive.

Doing it this way you can coast in neutral with the fuel cut off.

I I guess if you wanted you could turn the ignition off in gear , at higher rpm if you wanted but it would not gain as much as neutral would.

His van is an automatic so there's no clutch.

I was under the impression DFCO still used fuel. And EOC doesn't engine brake the car while DFCO does.

If you installed an injector kill switch, you could kill the engine without interrupting any other functions, like radio or fan. When you key back on, you'd get the usual momentary radio drop-out, but then all would return to normal. If you want to avoid multiple uses of the key switch, you could install a push button start alongside the key switch. That way the key could stay unchanged in the "run" position while you cut and restart the engine. But this is really all overkill in an automatic transmission car, because you can't cut the engine in an auto trans car while rolling (EOC, the big FE gains). And since you'd still be using the starter motor. So your best strategy, most cost effective and least expensive with no loss in fuel saving benefits is just to key off and on at lights longer than 10 or 15 seconds.

My grasp on is the engine is "turning" replicating a running motor , accept without any fuel consumption , respectively outputting no torque.
If less fuel is supplied then the idle requires the engine would shut down, If one was to supply less fuel then idle consumes and not cutting it off completely would be wasteful.


not all cars have the DFCO , I think it started showing up on *most* cars around 1999 or 2000

if dfco does use fuel it is very minimal compared to normal

DFCO does not always engine brake so this is a touchy area.
Ex. my grand am dfco in drive does not engine brake

No, I wasn't very specific. I mean doing this at home just to see what happens.

This works? I'm thinking of doing it at-home to see what happens. I tried pulling the fuel pump fuse and fuel pump relay but those aren't the injectors. My main goal here is to stop fuel from pumping in while keeping the van on, Otherwise (So ScanGauge II info is retained.) The gauge is due for an update in firmware though, At the 4.06 firmware it goes wonky if I shut the van off then turn it back on before the gauge has fully saved the info.

to clarify, are you looking to turn off your fuel injectors when stopped, and not have to restart before driving off?

That's the idea. Though now I'm thinking of doing it while coasting, too; It's beneficial at both times.

when youre not moving, the energy to keep the engine spinning on your caravan must come from fuel delivered to the engine.
if youre coasting, the energy can either fome from fuel, or through the drivetrain causing engine braking

a couple years ago i tried to think through retrofitting an auto stop start feature, long story short, the options are A: to use an injector kill switch and restart w/key or use a starter button or B: buy a car that comes with auto stop start

What you're doing is adding stop-start, but only doing anything on the stop side. Killing the injectors/fuel pump will stop the engine, turning them back on doesn't restart it if you're not moving/in gear, just like how your can doesn't start when you turn it to "run". You have to get the engine spinning again, either with the starter motor or the transmission if you're moving.

Killing the injectors while stopped kills the motor period, then it has to be restarted. Your van has this feature and as pointed out is done with the key. A hybrid does what you want automatically using only the brake and accelerator pedals. The hybrid can do this because it has a big battery and an electric motor capable of moving the car. So when you stop it killed or already had killed the gas motor, when you push the accelerator to go it starts moving the car with the electric motor and then restarts the gas motor but you hardly notice.
If its a problem with the scanguage powering down, wire it to a power supply that works with the key in the accessory posisition not just the run posisition, and don't turn the van key all the way to off just to accessory. Maybe your van is also diverting all power to the starter when you turn the key then I don't know.
I would not reccomend doing engine off coasting in that van. The power brakes will work fine for a little bit but then you will lose power assist and it will take much, much more effort to stop as well as losing power steering. Also you cannot restart it unless you come to a complete stop and put it in park.

In the build I used (adapted from others here at EM) I cut into the grounding wire for the fuel injectors. That will immediately shut down the engine, far better than the killing the fuel pump. A momentary switch for the injector kill and another for the start button, mounted right next to each other, maybe on the shifter itself. And there you go... DIY stop/start.

At Permalink #6 we get the real question. First off, 9999 is not infinity. Does the Scanguage actually display the ∞ character?

What you are asking is: Is there any way to hack the Scanguage to provoke an error condition (possibly a buffer over-run) that will display erronious information. That should suggest some strategies.

My question is: Why?

And a manual transmission would be of aid. Or is there a way to restart the engine with an automatic transmission?

That's useful, Thanks. I'm thinking of sending the Gauge in to update the firmware.

Thanks. Actually, I can re-start the engine in neutral with the van in "Accessory" mode. I've done it multiple times although it made a rather odd noise when I did it.

When I tried EOCing, I never did turn the key all the way off. I'd stick the van in Neutral and then switch to Accessory mode and back to Run fast (Which I later found shoots gas into the engine prior to starting it) and that would mess up the ScanGauge II readings in this particular Van/SGII Firmware combination. I also am able to maneuver the van without a power assist although it does require more muscle, And I'm sure I can stop the car without power brakes too as long as I press hard enough although I haven't done it much yet - In the driveway? Yes. On the road? That's an idea that has opportunity to come to fruition.

No, The "9999" figure is as close to the infinite symbol as that gauge gets. I'm asking how to get the van into a "No fuel is being put in" mode.

...

It sounds like you want either:

-A manual transmission

or

-An electric car

;)

What? It won't start in N? :eek:

This whole thread has me so :confused:

Some cars with automatic won't start in N, apparently this one is old enough that it will.

I'm feeling the same way why do we need six pages to try to figure out how to take something simple decide to find a way to do it that is impossible be repeatedly told that it is impossible ignore that but admit you just don't want to JUST FREAKING TURN OFF THE ENGINE AT STOPLIGHTS!!!!

Sorry but this is starting to get ridiculous. Do we have a icon for beating your head against a brick wall?

You have to bring your own:

http://i146.photobucket.com/albums/r...eadonwall2.gifhttp://i146.photobucket.com/albums/r...all-yellow.gif

Although I'm kinda partial to this one for here:

http://i146.photobucket.com/albums/r...urel_hardy.gif

I'm beginning to see a pattern.
I'm :confused: too, but I predict 101Volts will thank me.