Fuel consumption at idle?

[monroe74]

gary: "I used a DVOM to measure the fuel consumpition precisely"

Sorry if this is a dumb question, but I can't picture how you did that. Could you be more specific?

suspended: "to start them up requires a mixture of 10:1 or richer"

I assume you're referring to a normal start, using the starter. Would what you're saying apply equally in a bump-start?

I think there are probably various interesting tradeoffs, in comparing these two different methods of re-starting.

pale: "My d16Y7 idles at 2.5-3 gph"

You must mean .25-.3, right?

[GasSavers_RoadWarrior]

I presume the DVOM measurements took into account the known injector dead time for the known operating voltage and temperature?

[palemelanesian]

Originally Posted by monroe74

pale: "My d16Y7 idles at 2.5-3 gph"

You must mean .25-.3, right?

Typo! Yes, that's correct. I updated my post, too.

[suspendedhatch]

I'm not familiar with many of these terms I've been seeing. EOC, bump start...

By bump start do you mean push start? As in starting by dropping the clutch when the car is rolling? Yeah that doesn't take any unusual amount of fuel.

I've had to do that a lot lately since I've been experimenting with my DFCO RPM. Too low and the engine stalls out when I'm rolling to a stop, so a quick drop of the clutch and I'm up and running again. Usually do it by accident anyway since I engine brake.

[monroe74]

"EOC"

EOC is engine-off coasting.

"As in starting by dropping the clutch when the car is rolling?"

Yes.

I have fun doing this. I find that even slight momentum is enough (if the engine is warm). I've even done it in reverse, when parked on a slight slope.

"that doesn't take any unusual amount of fuel"

Thanks, that's helpful to know. I wasn't sure.

[dosco]

Originally Posted by PaleMelanesian

My d16Y7 idles at 0.25-0.3 gph when warmed up. A VX should be lower, I'd think.

Pale:
How much fuel does your engine use during a "pulse?"

[palemelanesian]

I aim for 2.0-2.2 gph. Full-throttle is somewhere up near 3.0.

[1993CivicVX]

Originally Posted by PaleMelanesian

I aim for 2.0-2.2 gph. Full-throttle is somewhere up near 3.0.

Maybe I should get a SuperMid. Knowing how much fuel my engine burns per hour would be very useful information, although I think gentle/moderate acceleration is ideal, even for P&G.

suspendedhatch: don't you mean D15Z1 not D15Z7?

[R.I.D.E.]

I see my engine drop to its lowest idle speed shortly after I begin the glide. I have no loads on the alternator above what the engine needs to run.

Pulse and glide techniques are very dependent on you individual driving environment. My daily drive is about 18 miles each way. The first 8 is 4 lane,55 mph for half themn 45 mph for half, with only 1 traffic light in that 8 miles.

The next 8 are much more congested with many lights, but if you time them you can miss about 90%. There is another stretch of about 3 miles with no lights, and another 3 miles stretch of about the same length, 45 in the first and 40 in the second.

If I drive this route religiously I can usually beat the old EPA highway ratings for any car (03 Tundra, 05 Scion XB, 06 Corolla, 94 Del Sol, 94 VX). I am retired so I don't have to get in heavy rush hour traffic.

I have lived in this area most of my life and know all the back roads, traffic patterns, even almost every pothole.

The way I used a DVOM to measure fuel was to measure the resistance of the sending unit. I removed tha back seat, and plugged the DVOM into the sending unit with it still connected. Since it was not grounded in the circuit it read the resistance values. I used the range from 3/4 tank to 1/4 tank and logged the readings in 1/4 gallon increments as I very slowly filled the tank.

Then I went to Poquoson where every road is 35 mph and they all end at a Marina. Traffic is virtually non existent. I drove a route of 4.5 miles out and back, left the car sit for 15 minutes while the battery voltage stabilized, with the ignition off, and took my voltage reading.

Then I checked my data sheet to see what my consumption was. this was in my brothers 91 Civic Hatch with throttle body fuel injection. Using EOC with a pulse to glide ratio of 1 to 3 I got around 76 MPG, and it showed about .24 gph idle fuel consumption.

regards
gary

[palemelanesian]

Originally Posted by 1993CivicVX

although I think gentle/moderate acceleration is ideal, even for P&G.

I disagree. So does this Autospeed article, and this gaslog.

I aim for 3/4 throttle and 1500-2200 rpm on the pulse.