To test out the search function for my future reference, I typed in our current discussion topic "ECU" in the search field and it returned with "no match found... either the results are too long etc etc..."

Did I miss something? Did I search correctly

 

You did raise a bunch of very good points, and that is a unique situation in which I wouldn't comment because I don't have much experience in that arena.

Just how many tickets have you had to where you have a "good track record" fighting them?

 

You seem to always make an effort to search I've noticed, so props for that! (it won't let me give you another +Rep bump though)

did you search by thread or by post? did you use only the word ecu?

it'll probably be a wash with just "ecu" in the query field.

I typed in "ECU tune adjust" and it brought up a bunch of threads including my 14page tech thread in the top 5 results:
https://www.fitfreak.net/forums/fit-...ater-meth.html

As well as the "fuel grade" thread I mentioned earlier:
https://www.fitfreak.net/forums/2nd-...-your-fit.html

You might wanna grab a snack.. that is not light reading by any means but in those two alone you could give yourself a thorough education in many aspects of tuning.

Multiple great contributors in each thread, lots of different view points.. good stuff.

 

Thanks, that's pretty much what I'm asking. To make sure I understand- you're saying that the ECU's original memory tables don't just get overridden by real data from the actual car's driving but that what gets written there varies based on driving habits. So that granny's half-throttle might not get the same response from the ECU as super-speeder's half-throttle because the car has 'learned' that since usually granny isn't usually in a hurry it won't give her car the same power?

Actually seems kind of weird to me. My prior car had a power/economy switch, which I understood but by my way of thinking the car should be thinking economy except when you step hard on the gas- then it should be obvious to the car that you're in a hurry! Otherwise the gas pedal would just be a three-position switch- faster, slower and stay at this speed.


And you can't search just for "ECU" because the search box wants a longer search term. Figuring out what exact search term will yield what you're looking for, and not seven thousand threads that AREN'T what you're looking for, is not easy.


Oh, and on the topic of tickets, I didn't get THAT many but I learned to deal with those I got. Haven't gotten a ticket in over 15 years although I did get pulled over twice the same night last year (3 AM, they were looking for drunk drivers, all I had in me was a lot of deli meats, no alcohol).

 

I hear ya, I am just teasing on that last bit. Did LOL about the deli meat part though

 

I was a regular guest on a late-night radio show and on Fridays a local deli would send over a lot of food. I don't know why but a lot of performers get really hungry after a gig and tend to eat a lot afterwards. And more so if the food's right there!

On the issue of tickets- used to have a red Integra, got pulled over a few times. Switched to a silver Infiniti, I don't think my driving habits changed, didn't get pulled over again for 14 years. People say that red cars being cop-magnets is a myth, but...

 

I could see that working up an appetite, it is still a job after all. Your brain burns a lot of energy, makes sense.

Besides who turns down good food?

Ah yes.. arrest-me-red. Even my GFs Volvo S40 gets her pulled over.. she doesn't get tickets either lol Maybe she just shows some tit or pouts and cries then gets let go...

My race car, which is red (street legal ) gets me attention sometimes, but fortunately no tickets. If I were a kid I'd probably be impounded. I've gotten two warnings, one was unfounded the other was so he could ask me WTF he was looking at

My Fit (black) has never gotten me pulled over, and I don't always drive so gently, FWIW. But it is also damn near silent, so Im sure that helps.

 

Eating a lot after a gig- it's psychological. When I worked in finance and used my brain for eight hours I wasn't so hungry, but a half-hour on stage is different. Musicians have told me the same thing, although their work is more physical than mine (some comics are more physical but I'm not that active on stage).

 

I'm trying to understand this thread, I'm concentrating and trying my best to see beyond all the 'feather ruffling' and posturing. I will say there's a few super egos at play and to be truthful, those are best left at the door.

True knowledge is measured by an individuals ability to explain the topic to others who are interested but unfamiliar with the subject. I was reminded of this fact a few years ago by the head of the research department my daughter had just landed a position in. It's good practice leading to the objective called 'defending a thesis'.

I'm thinking the whole thing boils down to this, post #25:


DSM A few questions, from the top, to your above response, okay?

Well it's a blend of both the tables and parameters that come in the ECU for the factory ans well as what the car learns from its driver's operating style.
1) What constitutes the 'driver's operating style.'?

So yes and no. It's a complex situation, but it sounds like you more or less nailed it! Then we start to venture into the realm of fuel trims, open v. closed loop, throttle tip in, temperature correction for air and coolant, etc.
2) Could you kindly define 'throttle tip in' and complete the 'etc'?

Bingo! It can do it, but it has to try it a few times to see what grannys particular car can get away with in a given set of situations! All other things being equal between speeder and granny (fuel/weather/load, etc.)
3) The things being equal refers to identical cars under identical conditions, correct? Any need to complete the etc? [I really find etc to be shortchanging when used in a technical discussion]

In a manual this usually effects how the throttle operates typically and only in drive by wire applications though..
4) Given the above explanation and the comparison between a 'speeder' and a 'granny' - if granny is perfectly happy with the economy her driving style provides [which will be better than the speeder, correct?] then to get the edge on a traffic merge or passing a semi or goofing with an Audi cruising the strip, for shitsandgrins, all she need do is drop it down a gear or two then get on it and any slight loss of 'performance' based upon her daily driving style goes out the window replaced by a torque loaded high rpm whine and she has a shit eating grin that only an i-Vtech might be able to give her, correct?

help me understand in layman's language_

 

No problem, and I'll apologize in advance for excessive use of "etc." there is just so much going on at any given millisecond in an ECU that in order to keep it to the basics I had to shortchange a few bits to keep the overall message straight forward as possible.

Operating style was referring to simply how the car is driven routinely.

For instance do you feather the gas and short shift every gear? Or do you ride out every gear to redline with greater than 50% TPS? That sort of thing. Obviously there is middle ground but those are the two extremes of the spectrum. Your driving style determines what sensor feedback the ECU sees and ultimately what decisions it makes under various situations.

Throttle Tip-In by its' self is just the rate of increase of the amount of fuel injected as you push in the throttle and on our DBW cars it also determines how fast the actual throttle plate opens.

Temperature correction for coolant or intake air does a few things and is actually pretty complex.

One way the ECU corrects for temperature would be when coolant temps or intake air temps get too high and make the engine more knock prone. Because usually when coolant gets hot it is because the combustion chamber is hot, so the spark plug and any other "hot spots" leading into or inside of the combustion chamber can trigger predetonation.

So usually what the ECU will do is for coolant temps above 200-210F every 10F increase will result in pulling at least 1* spark advance.

For high intake air temps which make for a hotter charge and lowers the remaining required activation energy, this makes the mixture more knock prone. So for every 10F above usually 110-120F intake temps you will typically lose at least 1* of spark advance.

So if you are driving along and your coolant is 210F and the threshold was 200F, while your intake air temps are 130F and the threshold was 120F you have lost a total of 2* spark advance. Which can be a lot.

Then if you are seeing knock retard on top of that, you will have lost yet more power as timing is pulled for safety. Eventually if you keep knocking this will drop you lower and lower on the spectrum of Min/Max Oct tables.

Depending on the ECU, this temperature correction for coolant and intake air can affect everything from the airflow smoothing factor, which is how the ECU "corrects" the VE table as temperature (or humidity in some cases) changes VE because a cooler or denser charge has different needs than a warmer less dense charge. So in order to properly gauge how much fuel is needed and how much timing can be used, there is a correction factor or coefficient used to tweak certain elements of the table to provide a more accurate picture of what is happening in the combustion chamber.

There are seperate enrichment tables for changes in temperature and even battery voltage because voltage effects injector response time as well as fuel pump performance and as little as .5v fluctuation can mean a huge difference in volume delivered at a given fuel pressure. So at 12v the injectors would need to be opened sooner and for longer then they would at 14v to deliver the same amount of fuel. So if you are cruising along at 13.5v and kick on the A/C compressor, the blower in the cabin and the A/C rad fan and ou drop to say 12v under cruise, the ECU references the BattVoltage Adjust table seeing that voltage is low, and it uses a higher deadtime correction as well higher IDCs to keep the engine stable.


For an example on temperature affecting fuel enrichment, let us take a look at cold starts. Because the fuel does not atomize as well more is needed then when you have a hot start. More fuel is required because when cold the oil is thick and the coefficient of friction is slightly higher. Think the difference between molasses and vegetable oil at room temperature. Which one resists motion more? The molasses in this cases simulates cold oil, and the veggie oil simulates warm oil.

Additionally because the ECU knows that it had to inject more fuel because it wasn't atomizing and inevitably some falls out of the air stream, there is more fuel that will "puddled" in the intake manifold and intake ports on the cylinder head.

This puddled fuel will evaporate at different rates at different temperatures and manifold pressure. This evaporation can skew the air fuel ratio seen by the oxygen sensors. So the ECU can correct for that as well, and can accordingly dial down the fuel delivery via the injectors a bit knowing that the stuff evaporating from the intake tract will still be used in combustion, so it will use that in reaching and maintaining the targeted Air/Fuel ratio.

I hope that helps clarify, and there is still yet more to it than that, and I'll try to expound later when I get home or if anyone has any questions on the above paragraph.

For number 3 you are correct all things being equal meaning identical car, road conditions, weather, driver input, vehicle weight, gearing, basically if everything conceivable were the same between the two for the sake of controlling as many variables as possible to try and provide an apples to apples comparison.

Well this last one is actually really quite complicated.

I am typing this bit seperately so I will be editing this post in a minute..

Edit:

For the most part yes she will be getting consistently higher mileage than the speeder, even if the speeder takes a day off from driving like a maniac and emulates her driving style.

His ECU will still be prone to running his car comparably rich under load in anticipation of hard driving, but if he permanently switches to granny style driving, over time the ECU will re-learn, and he too can garner consistently better fuel economy.

So if granny needs to get a jump on traffic or the Audi and drops a couple gears and goes WOT, the ECU will allow her to use the most aggressive tables the sensors, fuel and atmospheric conditions allow.

The first time she does it though, it may not give her MBT timing because of her past recorded drive cycles for the duration of the time her WOT exercise stay in closed loop

Above a certain coolant temperature, oxygen sensor voltage or RPM at a given throttle position which varies by rpm and is different from one ECU to another, the ECU will lock you in full open loop mode where the only sensor feedback that really matters is the knock sensor, she would have the benefit of the most aggressive spark advance and fuelling scheme the ECU is comfortable with. But not necessarily MBT, any knock, high coolant or air temps and things of that nature will slowly push her towards less aggressive regions.

So if we assume she has good fuel, “acceptable” coolant/air temps and and good voltage (among many other items) grandma could theoretically go straight from economy mode to kill mod.
Meaning that if everything checks out for the ECU, then there is no reason for it to not use the most aggrssive Max Oct spark/fuel maps available, and allowing her to immediately see the performance of the maniac driver. Thus putting the shit eating grin on her face.

But in doing so she will need to spend a while driving like she normally does before the fuel trims and everything else involved re-adjust back to her old driving style.

If she only does the one WOT run against Mr. Audi, it shouldn't take long, but her short term fuel trims (STFTs) will be all out of whack until she can even them out again and then when the STFT's are back hovering around +/- 1% the ECU bring her long term fuel trims back to where they were, though the LTFTs probably won't have shifted much if at all depending on how long the WOT session lasted..

I hope that helps and if I left anything out or missed something, or you just want clarification let me know.

That is the most concise way I could fashion that post so I hope I didn't omit anything or leave any glaring gaps. Again, let me know and I would love to clarify.

 

 

Sounds about right to me. People vastly underestimate these little 4-bangers and the ECUs operating them!

 

Here is a good link to explain tuning Density Altitude Tuning - Fuel Injection - Hot Rod Magazine. Keep in mind that premium is usually denser and needs less fuel compared to regular because of better burning characteristics, Even though regular works you might not hear knock and the ecu retarding timing and adding fuel but poor acceleration and poor mpg is usually signs of knock.

 

I have found that running at 1/2 throttle a mile or so coming and going on a trip to town keeps my ignition timing from falling off... There are so many houses going in recently that I have too change my route sometimes... It's worth it since I don't drive much and at 90MPH there isn't much room or response to avoid over laden logging trucks, deer, rednecks and retirees in big pickups and SUVs..

 

I only need to do 1/2 throttle to pass a car at 60 mph, anything else doesn't do too much. I am really enjoying my car this tank. I noticed that the last tank was better but not as good as this. My car just turned 10000 miles and wondering if thats why.

 

The tolerances are so tight ECU prevents running overly rich or lean fuel mixtures and synthetic oils reduce friction so well in the engines that have came out since the mid 80s on Euro cars and the 90s on most everything else that I think a car or motorcycle isn't getting it's best mileage and until it has at least 20,000 miles on it

 

Your right on the with the tolerances, but the newer ecu with ivtec adjusts to a even wider range of variables because it has a semi wide band O2 sensor with the MAF/MAP it can operate under a wider AF ratio. Synthetic oils is good for 1 percent mpg gain but thats adds up over the life of the car. Most mpg problems is because of short trips, and the ecu doesn't have a map for the cold or operating conditions. Short trips with long warms up hurts mpg the most. Premium gas keeps the motor running like it was supposed too even if sometimes the mpg is a little worse than regular but the average is always higher. My wifes car is a perfect example of this, it runs Ok and then a problem and next tank of premium to make it run right. 20000 miles is the stable point the car settle down and runs more consistent until the sensors deteriorate and then the mpg falls. If I average 37 mpg for the life time I will be happy its better than the highway average in mixed driving.

 

SilverBullet, Buddy I am having a problem getting my thoughts to reach my keyboard tonight.. I was thinking about how much the items I listed had done to slow the rate of wear in todays engines in comparison to cars that don't have these things... My last post appears to make no sense at all...Man I feel stupid right now.... I should have just said that todays cars and motorcycles don't get optimal gas mileage until about 20,000 miles and left it at that.

 

Its Ok, I understood it and I ramble on too. The more you write and then it starts making sense. Ive had a rough week too my mom and all. When you have a mind full of info and its not in order, you just start putting it down and eventually it makes sense, thats when you know your tired. Have a good night.