[e3sean]

Ok so i know when my car is back together everything has to get "tuned" what exactly does a "tune" consist of?? can they calibrate my maf during this or do i get that pre tune???

[e3sean]

someone has to know what they do when they tune it.. i here people say get your car tuned after any major upgrade all the time... well what does a tune consist of..??

[kuskye25]

i am curious to see what all it consists of as well, i see it referred to all the time too.

sorry no help im still learning....

[TurboLX]

timing, adjusting the fuel and air flow mix to it's mixed properly, data logging if needed, etc...

[kuskye25]

Originally Posted by TurboLX timing, adjusting the fuel and air flow mix to it's mixed properly, data logging if needed, etc...

ok timing i understand, but is there a module i buy or something to determine the air fuel mix, and how do you change the air fuel mix to what you desire.. thanks

[TurboLX]

its called an air/fuel ratio gauge

thats how you know if your leaning out or enriching it

[nolife]

What can someone really adjust that will change the air/fuel mixture and maintain that same air/fuel mixture long term? The stock unchipped EEC-4 should try to learn around changes the best it can. I would assume that if you set something that the EEC-4 can not compensate for, it will throw a code and resort to a default fuel map or you will be left with something that might run great at WOT but might surge, stall, or have idle problems.

Take raising fuel pressure for example. Short term that increase in fuel pressure will give you more fuel per squirt which lowers your air/fuel ratio. Through the o2 sensors, the EEC4 sees a air/fuel that is not "correct" and will reduce the injector pulse which will take the air/fuel ratio back up to what it thinks is normal. That is why there are chips and tuners. They provide new fuel maps (or fool the computer to thinking it is seeing something it is not) and provide the ability to control things to get those new desired air/fuel ratios. At least that is the way I understand it. Am I wrong?

[e3sean]

Originally Posted by nolife What can someone really adjust that will change the air/fuel mixture and maintain that same air/fuel mixture long term? The stock unchipped EEC-4 should try to learn around changes the best it can. I would assume that if you set something that the EEC-4 can not compensate for, it will throw a code and resort to a default fuel map or you will be left with something that might run great at WOT but might surge, stall, or have idle problems. Take raising fuel pressure for example. Short term that increase in fuel pressure will give you more fuel per squirt which lowers your air/fuel ratio. Through the o2 sensors, the EEC4 sees a air/fuel that is not "correct" and will reduce the injector pulse which will take the air/fuel ratio back up to what it thinks is normal. That is why there are chips and tuners. They provide new fuel maps (or fool the computer to thinking it is seeing something it is not) and provide the ability to control things to get those new desired air/fuel ratios. At least that is the way I understand it. Am I wrong?

ok that is what i thought a tune consisted of,pretty much reprogramming the computer..that i would leave to someone else..

[ryans88gt]

Originally Posted by nolife What can someone really adjust that will change the air/fuel mixture and maintain that same air/fuel mixture long term? The stock unchipped EEC-4 should try to learn around changes the best it can. I would assume that if you set something that the EEC-4 can not compensate for, it will throw a code and resort to a default fuel map or you will be left with something that might run great at WOT but might surge, stall, or have idle problems. Take raising fuel pressure for example. Short term that increase in fuel pressure will give you more fuel per squirt which lowers your air/fuel ratio. Through the o2 sensors, the EEC4 sees a air/fuel that is not "correct" and will reduce the injector pulse which will take the air/fuel ratio back up to what it thinks is normal. That is why there are chips and tuners. They provide new fuel maps (or fool the computer to thinking it is seeing something it is not) and provide the ability to control things to get those new desired air/fuel ratios. At least that is the way I understand it. Am I wrong?

EEC-IV does not learn anything, it just takes data and adjusts accordingly. The O2 sensors are not read at WOT and not read at much over 2500 rpms. They are basically for fuel trimming at cruising speed and idle. Adjusting the fuel pressure will make a long term change in the WOT fuel curve, but not in the idle and off idle fuel curve.

The computer does use the programmed tables to make adjustments. You are correct, by changing the data in those tables, you change how the computer responds to certain conditions. Piggy back controllers go one step further and allow much more adjustment of the EEC as well as standalone mode. A lot of tuners prefer a complete standalone system.

[sneezingfox]

Check out TwEECer...

[nolife]

Originally Posted by ryans88gt Adjusting the fuel pressure will make a long term change in the WOT fuel curve, but not in the idle and off idle fuel curve.

Okay, I found some info on the EEC-IV that discusses WOT

The ECU controls both the fuel mixture and the timing with the fuel mixture operating in either "open loop" or "closed loop" mode. Anything external to the EEC that tries modify the fuel mixture at points where the engine is in closed loop operation will cause the computer to attempt to compensate. That’s why trying to change the A:F ratio and "fool the computer" cause more problems than it’s likely to solve. Timing and WOT fuel settings aren’t closed loop functions, and can be changed without the computer trying to correct them.

I did not find much about what other conditions are needed for open and closed loop operation. I assume operating temp is in there somewhere.

According to some sources, the EEC-IV does adaptive control and long term corrections. Funny though as this page starts off with "There is much confusion about how Adaptive Control works especially at WOT." This page gives an example as well but also states the O2 is not used at WOT like you already pointed out.
Either way.. If I get bored, I'll read more about it. I'm not making my own chips so I think I know all I want to for now.

On that note, I do need some test and tune time with my car

[tvc2389]

u can get a FMU which they are able to tune ur car off or an AFC

[tehdwarvenn]

whats WOT stand for? seen it alot...

[HMUSN]

wide open throttle.

[tehdwarvenn]

thanks HMUSN ^.^