I keep seeing some people say you can and some you can't. So if your computer has learned a certain way of running your engine with this gas and that air mixture and so forth, can you undo it and make it re-learn by unplugging the battery, or not? I know with alot of cars you can, but I see people say you can't. I understand you cant undo a defective program on the computer, but can you at least undo the way the computer runs your engine and set it back to the way it was brand new?

 

Lemme see if I can rephrase this..

The PCM is a EEprom format of memory..Dropping power to it or whatever home remedy will not undo any program glitch..Must be reflashed

Furthermore..The H3 does not posess the predicitive learning format as the H2 does.

 

I figured you were going to repost that EEPROM memory allows you to erase and rewrite a new program. That I understand (since that is my field ya know ;-) ) I guess my question should have been, is there another type of memory on the H3 for the learning of your habbits? EEPROM memory usually doesn't rewrite itself. Somebody has to do it. Does the H3 computer adapt to your driving at all, or does it just run the same program from the second you drive it off the lot? I know you said the H2 adapts, but I wasn't sure about the H3. I just was curious as to whether the way the computer controls your engine changes at all from when it is brand new. I read somewhere it supposedly changes depending on the Octane you use but I think that is the engine knock sensor and not the actual program. I'm just trying to get a better understanding on the H3 computer. Car computers and business computers are a little different, so NO I don' t know what the H3 does

You get what I'm trying to ask correct? and I'm not being smart about it. Just want to know if it changes at all.

 

I can tell you from trying it out last week that dropping power to it only made me have to reset the clock[:@] I filled up after I dumped the power and went to 214 miles till the light came on tonight, filled it with 20 gallons..10.7 MPG

 

Was that with or without you towing something?

 

HG..The puter will adjust the timing to compensate for low octane or to prevent predetonation..but that's it..It does not learn your driving habits as I said before.

 

OK That's what I wanted to know. I wanted to know what it does to adjust the engine. I understand when you said it doesn't learn, but I wasn't sure what it does to actively adjust things. I asked because I switched from 87 to 91-93 octane and at one point thought I noticed the engine run smoother, but as I have been switching back and forth, I realized it really doesn't make any difference at all. Maybe I get a little better gas mileage, but not enough to justify using the higher octane. I'll just stick to 87 all the time as the manual says. I'm getting tired of all of these What-if tricks to get your H3 to perform better. I have my K@N filter, some extra air flow holes, and going to get my exhaust hopefully in December after we close on our house. After that, I'm going to start looking into my SCCA license so I don't think I'm going to invest any more money on this. And, good morning!

 

no towing, normal driving conditions

 

Hi Mike...Don't misunderstand me if I seem short tempered..it ain't you and I apologize if you felt any meaness from me...



Seriously..The programming of the H3's are for 87 octane...As you may already know, An Octane rating is a number given to fuel pertaining to the ability to burn..Lower numbers means faster burning (Low compression engines or retarded timing accomodates this lower octane)..Higher octane of course is for Higher compression or more advanced timing, because the higher octane fuel (usually 91+) burns slower and longer (girls like that part)...Anyways, if your car is programmed for 87 octane, then that means the timing is set for that..if you put in 91 octane or higher, that will do nothing positive for the engine. In fact, it could harm the engine with carbon deposits..On Hot days while driving hard or heavily loaded up hill, the timing will naturally advance to the point just before predetonation will occur..But the range of this timing control is narrow..So if you want to have the right fuel octane for all conditions, 89 in the summer and 87 in the winter will serve you just fine for all conditions.

 

Too Late! I already saw your original thread, and as I laughed out loud, my co-workers looked at me with an odd eye...... They often tell me what you originally said jk

That's actually very good info. Thanks for taking the time to type it out. When you see everybody having their own theories on things, you tend to want to try them. I have replaced radiators, exhaust systems, wired every kind of electronic dohicky you can think of in cars, but still am a novice when it comes to engines. My mother's bf was a auto professor at a college for 20 years and he even told me "don't waste your money on the high octane unless you need it" but I like to tinker.

Anyway, it takes ALOT to offend me buddy I work for almost 400 attorneys. There is NOTHING you can say I haven't heard before!