Idle second equivalent of starting an engine

[Snax]

I forgot about the 'acceleration pump' map. This map briefly but significantly enrichens the mixture and will undoubtedly kick in any time the computer attempts to accelerate rpms to idle from the starter rpm. So yeah, shorter off-times probably don't gain much if anything.

[iwilltry]

I agree there are many factors that could have a significant effect. All theories seem valid, but where is the empirical data? This is the "experiments" section of the forum after all. Leaving the question of additional wear on engine and/or starter aside, has anyone with a scangauge tried this experiment? Worst case it would prove inconclusive. Best case you might actually know how much additional fuel you consume per start and how many seconds of idling it is equivalent to? If I had a scangauge I'd try it right now... how can you resist ?

[trebuchet03]

^^ Yeah, if no one steps up, I'll do it.. But not this weekend, next weekend (barring anything coming up unexpectadly). If I get the ignition into run and let the SG start up before cranking, it will record properly.


That being said, UPS has done this study... Killing the engine for all deliveries is best... But numbers are nice

[Snax]

I just don't think the SG will be able to provide reliable data on it. A better empirical test would involve using a pre-measured small quantity of fuel, and I'm not sure how one would easily do that with an EFI vehicle without using a remote pump and fuel tank.

[iwilltry]

The results are in. I logged my fuel injector pulses during and after starting and determined exactly how many seconds of idling consumes the same fuel as starting. See the writeup here: http://www.iwilltry.org/w/index.php?...g_your_engine?

Results:
Starting my car ('92 geo metro) consumes fuel equivalent to 6-7 seconds of idling. But that's for "starting followed by idling". The additional fuel consumption appears to be almost entirely the result of a higher idle speed setting for the first 20 seconds after starting. So if instead of idling, you start moving (ie extracting useful power from your engine) within a couple seconds after starting as I assume we all do, then starting a warm engine effectively consumes no additional fuel.

[Snax]

Nicely done.

Seems to me to be a valid arguement for EOC'ing to a stop virtually every single time - barring additional wear factors from excessive starter use.

[8307c4]

Originally Posted by trebuchet03

Don't assume Get oil analysis I run dino oil with 10,000+ mile service intervals - lots of starter use etc... No abnormal wear, dilution, etc. Unless Blackstone is consistently telling me untruths I do have a engine off criteria though - minimum coolant temperature of 166F.

No abnormal wear, translation: It DID wear!
How much is anyone's guess, the mechanic decides what is normal here.

It's not like you had your engine torn apart after 2-300,000 miles and shown no internal wear.
Not like you've driven with the engine pinging the governor at the rpm redline for 20 minutes solid.
Not like you take corners so hard the engine oil light comes on and stays on, but you keep going.
Not like you take the engine on severe inclines at full rpm's, for as long as necessary.
Not like you've raised the governed limit on an engine before.
Unlikely you've ever flipped one or ran it upside down for a short period of time and it stayed running.
Not like you ran the oil out of it because you forgot to tighten the oil filter properly and it all leaked out, 5 miles later you noticed, added 4 quarts and to this day you can repeat any of the above, and with the exception of running it dry, you have, numerous times.

You don't actually have to abuse them, some is accidental, some is normal daily driving, believe it or not. The above may sound far fetched, but a lot of cars go through a good part of that in 200,000 miles.

And once you seize an engine, I can almost guarantee you'll never run dino again.

Now if one or the other smokes a little after I've done the above to them a good 50-100 times, that I find acceptable. But no more seized engines, that is hoarse KRAP.

[trebuchet03]

Originally Posted by 8307c4

Not like you've had your engine torn apart after 2-300,000 miles and shown no internal wear.
Not like you've driven with the engine pinging the governor at the rpm redline for 20 minutes solid.
Not like you take corners so hard the engine oil light comes on and stays on.
Not like you take the engine on severe inclines at full rpm's, for as long as necessary.
Not like you've raised the governed limit on an engine before.
Not like you ran the oil out of it because you forgot to tighten the oil filter properly and it all leaked out, 5 miles later you noticed, added 4 quarts and to this day you can repeat any of the above, and with the exception of running it dry, you have, numerous times.

But once you seize an engine, I can almost guarantee you'll never run dino again.
Well, at least that was what did it in my case.

Wow, really defensive today

In any case, you assume a lot
Not like you know me or my experiences

[8307c4]

Originally Posted by trebuchet03

Wow, really defensive today

In any case, you assume a lot
Not like you know me or my experiences

Yeah but this is like arguing about the benefits of sunlight with a blind man.
The man wants proof, now you can lead this horse to water, but you can't force it to drink.

Just because assume means accept without verification or proof...
It also means take to be the case or to be true!
It means 'take on,' such as:
If you assume extra wear, this means it wears more.

In this world if I needed proof for what every dick and harry spouted off I would still be where I was 10 years ago, now y'all can go get drunk instead of me, I won't stand for the garbage and I don't need proof of my own experiences.

Proof or not, if it looks like a duck, quacks like a duck, walks and talks like a duck.
You know that's a duck, my chances of being right are 90% or better, case like this I ALWAYS assume.
Because given the odds, I'm right more often than not

So, you DO assume extra engine wear running dino.
No abnormal wear IS wear.

........
Btw some folks claim if you hold the horse's head under water long enough it eventually has to inhale some
Me, I'm long gone before it comes to that, I let them figure it out on their own.
And if they never do, it's not my problem.

[omgwtfbyobbq]

Go speed go!