Happinen Hank

Ive been trying to figure out which tables will increase the fuel at idle and have had very little success. Ive spent months reading through the stickies and seem to be getting no where. I have adjusted the injector constants with no luck and finally the PW vs voltage offset and seemed to get the added fuel i need but then all of a sudden it went way rich low 12s. Everytime i change something and it seems to be getting to where i need it and then all of a sudden it goes way lean or way rich. I have spent many months getting no where and if nothing else does anyone know of someone who is located in central California who does tuning? There is an overwhelming amount of information but a lot of it lacks what seems to be, the details. From what I seem to notice its like most of the people on here who are successful have some sort of computer programming background and i'm sure that helps. For the guy like myself who is great with tools but lacks big time in the computer tuning world, i'm lost. All input would be more than greatly appreciated.

3.8TransAM

MAF tables vs. grams/sec is where u need to poke around.

Best results use a wideband for accuracy(huge time saver here)

This is all in the stickies up top. If u read them once, read them three times

later
Jeremy

Happinen Hank

I due have a wideband and I have read a great deal on the maf table debate. What i got from it was that most people say dont touch unless you have modified your MAF which i have not. I have read a lot of your post and can say you obviously know what your talking about. So off to the the maf tables i will go. Just to make sure i'm on the right track use the maf tables to get my idle solved. Then the AE tables for cruise and the PE tables for WOT.

RednGold86Z

iTrader: (1)

What are your engine and injection system modifications? Different injectors require changing the injector constants. They might also need some change to the injector offset vs VBatt, but that comes after the Injector constants change, and large scale MAF table (if necessary) adjustments.

Big cams make idling in closed loop more sensitive, and sometimes impossible.

Happinen Hank

383, ZZ4 cam, vortec heads, SDPC vortec manifold, superram intake, supercharger pushing 6-8PSI with 42# injector. I did change the injector constant to 42 pounds.

Grumpy

If you think idle is fun, just wait until you turn the wick up at WOT.
You're going to have to be really rich in the low end of PE mode to have enough fuel to carry you over to max HP..
It can be done, but you're going to abuse the code to get it workable. Note *workable*, not *right*.

And BTW, I've had a hand in some MAF stuff that's run 9's.

RednGold86Z

iTrader: (1)

For the idle, it's probably just the injectors giving you a little problem, so my guess is that it can be fixed with the injector offset vs VBatt. If it's lean, raise this by 10% across the board, and try again. Go in large chunks, like 10% first, then 5, 2, until it's where you want it.

It might not be easy to have closed loop and 42's on that small cam. You're probably on the limit of the injector minimum pulsewidth (where a little too small of a pulsewidth won't inject much at all, but just a little bit longer might inject too much). It might be switching into single fire mode, also. Are you changing BOTH injector constants to 42? You should.

You'll probably run out of MAF pretty soon with that blower on there. You'll have to fudge the PE, as Grumpy says.

Happinen Hank

The MAF tables give me the needed fuel but heres the problem everytime i make a change and the AFR's go down to like 14 the computer immediately begins to compensate and brings it right back up to 16.6. Same with the PW vs battery voltage or any other change i make in closed loop. What am i missing to keep the computer from making these changes? Do I tune entirely in open loop and leave it or can it be done in closed loop? Like Grumpy stated WOT is already really rich in the 11. I have had much more success with open loop tuning but from everything i read it seems as though closed loop is better or just more of a safety precaution. Cant figure out why the computer keeps taking my AFR's to 16.6 my stoich is set at 14.7. What would cause it to do that.

RednGold86Z

iTrader: (1)

ahh, I see what you're saying now.

are you using TunerPro RT?

There's a table starting at 046B, called Closed Loop Rich/Lean threshold vs Airflow. It's 9 rows long. With xpoints of 0, 8, 16, 24, 32, 40, 48, 56, 64 grams/second. There is 1 column, with a lable of millivolts. And the conversion is 4.425*X.

At the lower airflows, 0, 8, and 16, you'll want to increase this from the stock-ish 600's up to 700 or more. This will tell the computer to keep adding fuel until the EGO voltage goes above this, and will only remove fuel until the EGO voltage goes below this. So basically, you'll see EGO voltage swings around this point, rather than the leaner points in the original calibration.

junkcltr

iTrader: (1)

The main problem with $6E and $8D or any other non-boost code is that when not in PE mode it is trying to acheive 14.7:1 in closed loop WHETHER you are in boost or not. So if you part throttle it and have boost it is way too lean. WOT (PE mode) will be fine though.

Even if you get it tuned in closed loop from 16:1 to 14.7:1, you are still going to have a problem when in boost. Only solution is open loop or boost code.

EDIT: In terms of the erratic AFR at idle. Do you have headers with the stock O2 sensor down at the collector? If so, does it act lean when sitting idling for a while, but is rich after driving and coming to a stop? Does the O2 voltage swing between 200mv to 800mv or does it just wiggle a little bit around 450mv when at idle?
If all this is true then it sounds like a cold O2 sensor.

Happinen Hank

This afternoon I'll try the rich lean threshold table and see how that goes. Junkcltr made some interesting comments with relation to the code being a non boosted code. My question then. Is the only way to run a boosted code is to convert to map and use a two bar sensor or can it be done with MAF? Is their a code already available I can work from, because writing code goes far beyond my abilities. Wondering if my combination, being a little on the light side of things will really vary that much in cruise, especially since the only time I actually see boost is at full throttle.

RednGold86Z

iTrader: (1)

I guess the question is, is have you taken it to full throttle, and does it stay rich enough? Does it ever get tooo rich? Does it stay rich enough at very high RPMs?

Basically, the MAF can't "control" the fueling at high RPMs (but the computer can be TOLD what to do, sorta), and it certainly can't control the spark in the same way as boosted code (the tables for spark max out at LV8 (load) of 208, but you could see up to 255).

A DUAL MAF setup might be able to give you the control you'd need. But that's a whole different bag of worms. We should make a DIY dual MAF "kit" that includes any software changes, or just make a larger MAF housing and lie about it's flow and lie about the injector size.

Happinen Hank

Yes i have taken it to full throttle and it stays plenty rich enough stays in the 11 which i think is to rich even for the boosted application. Timing I'm just running basically the stock timing smoothed it out and broght in all degrees by 2000 RPM and then took a few degrees away at the top end. I'll worry about the timing of course once the fueling is taken care of. The larger maf idea sounds pretty good. I don't think i will have a problem with getting enough fuel thats why I went with such a large injector. You did mention though that the injector simply might not be able to fire such a small amount of fuel and is reverting to single fire. I honestly hope not, but I have been able to keep the AFR's at a steady 14.7 in open loop so hopefully closed loop with the changes to the rich lean offset will work for me. What size injector would you recomend for my application? Didn't get a chance to make the changes today had to help a friend move. One thing with the rich/lean table is that the rows start with 8 and go up from their but the eighth and ninth row say the same thing so I'm guessing it is just a mistake in tunerpro. Don't think its any big deal. I'll be able to get back into it tomorrow even though its going to be a 108 degrees here tomorrow, this heat wave needs to go away. Makes sitting in a car tuning, like sitting in an oven.

Happinen Hank

The closed loop rich/lean threshold table did it the car can now idle at a steady 14.7 or their abouts. Had to raise those table quit a bit into the 900's to get everthing smoothed out. Now when tuning for cruise should i use the AE tables or should I use the MAF tables or maybe a combination of both. Funny how I answer my own question. One thing of interest in my reading through the various posts. Was the converting to MAP. In one article it stated all I would have to do is move the MAF wires to a MAP sensor and then repin and remove some of the wires in 165 ECU as well as move somes wires on the ECU harness itself. The question I have is can I still use my 165 ECU and just load what I believe was the 808 bin or any other MAP bin and tune from their and do you think that would be a better solution for the future? Eventually I would like to throw around 10-12 PSI at this thing and see just how scary fast I can get it. For now I'll hopefully be moving forward and getting the tuning to a point where i can smog it. By the way my smog is already past due. What i really need is a break in the heat so I can stand to be in my car a little longer than 15 minutes before heat stroke sets in. Hopefully for your sake its cooler in that part of the world. Thanks again for the input and your patience, I'll continue to keep you updated.