cfg83: If I kill this car, then it's off to the new car lot for me. I don't have the skills to fix it.
Does this mean you think Engine Off Coasting would ruin your car??
It means that I don't know if Engine Off Coasting will hurt my car or not. I don't know the physics of it. I think I know that I am "tapping the flywheel" to turn the engine over, but that's about it (sometimes I can do a really clean "bumpless" tap at 30 MPH in 5th gear). A good chunk of this time I read this forum and I then go and do alot of "homework". Part of that involves reading long threads in this forum and part of that means going into the nether-reaches of the net to figure this stuff out.
Carlo, I am not chastising you or anyone else. I am just trying to help those who seem to be interested in FE. In my opinion and experience, I consider the strain on a transmission to be negligible compared with coasting in gear. Either way you are feeding the power backwards from the wheels to the engine. Engine off you are not feeding power backwards except at the instant of bump start.
For a while I have been bump starting in 4th gear below 40 MPH. I do not bump start below 25-30 MPH very often. Real slow bumps is where the jerking happens.
A while back I read in a GS post, that Dan Krouse on his commute, had his engine running 34% of the total time. I have not measured my own % but would not doubt that it is in the same area. Remember, when the engine is off, you are using no fuel.
CFG83: Their is some difficulty in answering your questions, for several reasons, none of which have diddly to do with you knowing or not knowing anything about cars. I think you'd find that most the people on here know something, largely because their are a lot of things that just don't seem to get done like you want, unless you do them.
As far as the kill switch, it's use, it's effectiveness and so forth, a lot of that is related to the car you are driving. For example, I am driving an 89 Honda Wagon, which is basically a DX in a box. I put a kill switch in, but I quit using it, for several reasons. Primarily, for me, it came down to the fact that if you turn off the engine, the oil pump is no longer pumping, and consequently each time you restart, you have a period of time when the engine is turning with little or no oil pressure.
I hate working on my car, consequently the savings which I was getting was not worth it, IMO, in relation to the potential wear and tear. Added to this, a restart puts an additional requirement on either the starter, or on the clutch/flywheel. In either case, same, same, no likey unnecessary repair.
Finally, on my Civic, I would always get a CEL whenever I killed the engine, irrespective of how I did it and I would have to turn the key off, then back on and it just got to be a potential distraction issue.
Also, with regard to Oxygen sensor's, I have a 4 wire sensor, which I wired in so I could monitor the voltage. What I discovered was that whenever the throttle is closed, the fuel shuts off as long as my rpm is over 1250 rpm. Consequently, most of the time, my fuel would have been shutting off, anyway.
Regarding O2 sensors, a 1 wire and 4 wire unit both are narrow band sensors. They both measure the same thing and are designed around 14.7 to 1 as an optimum air fuel ratio. They typically are utilized by the ecu to control the fuel by putting in a little more, until the voltage goes up and then putting in a little less until the voltage from the sensor goes back down.
A wide range sensor is typically 5 wire, and can sense a much leaner fuel condition and report it to the ecu. However, the ecu has to be one programmed for the wide range sensor. Up until recently, the 5 wire unit's were used primarily for ecu tuning and in Honda Civic VX's. Consequently they have not been in great supply and therefor were significantly more costly. If you have a car that requires one, it probably is something which will get better mileage. If you don't, you can theoretically make the changes to accomodate one, but unless your into twiddling and fiddeling, it isn't probably something you would want to do.
If you have any questions, or you decide you want to get your hands a bit dirty, just give a shout.
In CA., you can normally still manage to work on your car, if you have to. However, the cold winds which we've had make it pretty miserable, recently.
CFG83: the kill switch I imagined (and some use) is a momentary contact, press it and the engine dies. release it and you have to spin the engine up again via starter if stopped or bump start if moving, or if you never took it out of gear it will have powr again.
re trans wear, if your car is the sort that is towable behind an RV then no worries. If not then still probably no worries, but not a guarantee. This mostly applies to automatics but I think some manuals (i.e. old volkswagens) wont move the tranny oil to all the right places without the input shaft turning and those spots wont get as much lube as normal.
CFG83: Their is some difficulty in answering your questions, for several reasons, none of which have diddly to do with you knowing or not knowing anything about cars. I think you'd find that most the people on here know something, largely because their are a lot of things that just don't seem to get done like you want, unless you do them.
As far as the kill switch, it's use, it's effectiveness and so forth, a lot of that is related to the car you are driving. For example, I am driving an 89 Honda Wagon, which is basically a DX in a box. I put a kill switch in, but I quit using it, for several reasons. Primarily, for me, it came down to the fact that if you turn off the engine, the oil pump is no longer pumping, and consequently each time you restart, you have a period of time when the engine is turning with little or no oil pressure.
Ok.
Quote:
Originally Posted by Gary Palmer
I hate working on my car, consequently the savings which I was getting was not worth it, IMO, in relation to the potential wear and tear. Added to this, a restart puts an additional requirement on either the starter, or on the clutch/flywheel. In either case, same, same, no likey unnecessary repair.
Finally, on my Civic, I would always get a CEL whenever I killed the engine, irrespective of how I did it and I would have to turn the key off, then back on and it just got to be a potential distraction issue.
At least that's not an issue for me with key off/key on. The check engine light goes away when I bump start.
Quote:
Originally Posted by Gary Palmer
Also, with regard to Oxygen sensor's, I have a 4 wire sensor, which I wired in so I could monitor the voltage. What I discovered was that whenever the throttle is closed, the fuel shuts off as long as my rpm is over 1250 rpm. Consequently, most of the time, my fuel would have been shutting off, anyway.
That's probably different for me. What I have gleaned from the saturnfans.com website is that the fuel injection is reduced but never quite off. Your Wagovan's behavior makes sense to me.
Honda ECU Programming Rule:
closed = 0
idle = 1250
if (( throttle = closed) and ( RPMs > idle)) then fuelInjection = 0
Quote:
Originally Posted by Gary Palmer
Regarding O2 sensors, a 1 wire and 4 wire unit both are narrow band sensors. They both measure the same thing and are designed around 14.7 to 1 as an optimum air fuel ratio. They typically are utilized by the ecu to control the fuel by putting in a little more, until the voltage goes up and then putting in a little less until the voltage from the sensor goes back down.
A wide range sensor is typically 5 wire, and can sense a much leaner fuel condition and report it to the ecu. However, the ecu has to be one programmed for the wide range sensor. Up until recently, the 5 wire unit's were used primarily for ecu tuning and in Honda Civic VX's. Consequently they have not been in great supply and therefor were significantly more costly. If you have a car that requires one, it probably is something which will get better mileage. If you don't, you can theoretically make the changes to accomodate one, but unless your into twiddling and fiddeling, it isn't probably something you would want to do.
If you have any questions, or you decide you want to get your hands a bit dirty, just give a shout.
Ok. I have the digital A/F gauge from jaycars.com.au. *After* I received the gauge I realized it preferred a wide band 02 sensor. My Saturn only uses a narrow band. Later on the gauge designer responded to my e-mail and told me that it will still work for me. In the meantime I spent a week trying to figure out the difference between 02 sensors and whether or not it would work on my Saturn. I want to splice into the same sensor (not a separate standalone 02 sensor) that my car's computer uses because I want to see what the car's computer sees when it comes to the 02 reading.
Quote:
Originally Posted by Gary Palmer
In CA., you can normally still manage to work on your car, if you have to. However, the cold winds which we've had make it pretty miserable, recently.
Tell me about it. I burned my finger on the cigarette lighter on Saturday and iced it into a callous. On Sunday, I was staring at stuff under the car for my next "mad scientist" project, and when I got into the house, I couldn't tell which finger was burned because they all felt like they were calloused from the cold.
CFG83: the kill switch I imagined (and some use) is a momentary contact, press it and the engine dies. release it and you have to spin the engine up again via starter if stopped or bump start if moving, or if you never took it out of gear it will have powr again.
Ok, this is what I was failing to describe properly, a "momentary contact" switch. The "never took it out of gear it will have powr again" is what I was hoping to hear. In fierce LA traffic, I would need "instant power", so to speak. With a switch like this, I would be able to emulate Gary's Honda Wagovan behavior (that he gets for free!!!! ).
Quote:
re trans wear, if your car is the sort that is towable behind an RV then no worries. If not then still probably no worries, but not a guarantee. This mostly applies to automatics but I think some manuals (i.e. old volkswagens) wont move the tranny oil to all the right places without the input shaft turning and those spots wont get as much lube as normal.
I have a manual transmission. This sounds like a saturnfans.com question. I seem to remember that Saturns are "RV-Tow" friendly, but that's about it.
I am just trying to help those who seem to be interested in FE. In my opinion and experience, I consider the strain on a transmission to be negligible compared with coasting in gear. Either way you are feeding the power backwards from the wheels to the engine. Engine off you are not feeding power backwards except at the instant of bump start.
For a while I have been bump starting in 4th gear below 40 MPH. I do not bump start below 25-30 MPH very often. Real slow bumps is where the jerking happens.
That is a question I have that is more relevant to this thread. What are your "bump start" rules after you have activated your kill-switch? My LA traffic makes freeway bump starts problematic. I do have a few zones along my route that I think are bump-start friendly. Here are my bump start rules :
- Relatively flat road that I know
- No one following me
- 40 to 45 MPH speed limit
- Spedometer usually at 40 to 45 MPH
- Key off, wait 1 second, key on (or kill switch if installed)
- Coast down to 30 MPH
- Bump start in 5th gear
If I tap the flywheel just right and push the clutch pedal back down real fast, I don't even feel the bump.
Quote:
A while back I read in a GS post, that Dan Krouse on his commute, had his engine running 34% of the total time. I have not measured my own % but would not doubt that it is in the same area. Remember, when the engine is off, you are using no fuel.
I was thinking of locations for the switch and decided the index finger on the shifter hand was best. It should be super easy to get to, like easy enough to use even during shifting or during engine braking (according to my scangauge the car is still using fuel while decelerating in gear), and especially coming up on stoplights/etc.
The wires are hooked up to the "Normally Closed" part of the switch and will be run down the boot, under the counsel, and through the firewall and in series w/the injector. Hope the switch can handle the current.
Now only if my urethane glue job would hurry up and dry
). 
Linear Mode
