robertfrank

iTrader: (27)

Ok guys, I have been having a bit of a lean issue for a while with the hot rod. When it's cold it seems to be running lean as hell, if I raise up the open loop AFR multiplier vs cts in low cold areas it seems to get even leaner. Here's a small datalog to show what i'm talking about. I also have my current BIN enclosed. Can somebody give me a clue as to what I might be doing wrong? I'm also curious as to what you guys might think of my spark tables.

xch3no2

I know that the EBL openloop-AFR v CTS multiplier works inversely to what might be intuitive.
ie. negative numbers are richer.

Choke AFR as well as OL AFR v CTS adjustments have been necessary for me.

robertfrank

iTrader: (27)

ARE YOU SERIOUS!?!?!?! Ok now I feel like a dipshit. I didn't know I was doing it backwards,lol. I tried doing it the right way after reading this and it did help out alot. I believe with some fine tweeking I can get it right. What does the Choke AFR do?

Saar

think of choke as the transition from cranking fuel to open loop fuel.

RBob

iTrader: (1)

Yes, think of it this way: a smaller AFR value is richer. With a negative percentage adjustment making the AFR a smaller value.

Also referred to as after start fuel. There is also a choke or after start SA. These get decayed out in a short period of time. About 2 minutes on a cold engine (say 40* F). and within a few seconds on a hot engine.

Basic purpose is to help prevent the engine from stalling immediately after start up.

RBob.

robertfrank

iTrader: (27)

Ok since we are on the subject, what other tables are in "reverse"? So that way I can figure out whether or not I screwed up somewhere else.

Ronny

iTrader: (1)

BANNED FOR LIFE FOR USING THE S WORD !

You can also enrichen using the tables for open loop rpm/vac. Stock I believe is 14.7 and mine currently is at 14.0

RBob

iTrader: (1)

The tables aren't in reverse. A richer AFR is a smaller number. Reducing the table value with a more negative adjustment makes the values smaller. Thereby richer.

Another thing to do is to look at stock tables. As the temperature is lower, the table values are more negative.

RBob.

robertfrank

iTrader: (27)

Are the AE tables the same? such as the lesser the number the richer? CTS and RPM? Just trying to cover all bases here.

RBob

iTrader: (1)

The AE tables are based on injector PW, not AFR. So the smaller the PW the less fuel (leaner).

RBob.

robertfrank

iTrader: (27)

OK I have been playing around with the tune lately and for some damn reason it is still very lean when the engine is cold. I have noticed that it doesn't seem to richen up until the NB O2 "wakes up". I lowered the Open Loop AFR Multiplier CTS tables quite a bit in the 56 range and down and it didn't seem to have much effect. Also, when I'm driving around I have a lean condition that doesn't seem to want to go away either, it only seems to come in when I give it about 8-10% constant throttle. It will bounce around 15.8 to sometimes 16.2. If I give it a touch more gas or lift off the throttle it richens up. It's really starting to irritate the ever loving hell out of me. I have richened up the VE tables in this area (between 20-30 map @ 1800-2200 rpms) and it hasn't helped either. what am I doing wrong?

RBob

iTrader: (1)

I don't imagine that it would be an injector duty cycle issue. As this is at low to mid RPM, correct?

You can also use the AFR vs RPM & VAC to add fuel in that area. It sounds like it is at a particular RPM and vacuum that is causing the issue. As increasing or decreasing the throttle slightly makes the engine go rich again.

Remember that the commanded AFR table is based on RPM and VACuum. Not MAP.

It isn't going into lean cruise by any chance?

RBob.

robertfrank

iTrader: (27)

To be honest I don't know. How do I check for lean cruise? I know I turned highway mode off for VE learns. I checked my AFR vs RPM & VAC tables and in those areas i mentioned earlier I have it set at 13.50. Another thing that is bugging me is that every now and again the car will stall out on me. It seems to do it when I come out of a turn or if I let the car idle for a bit when it's cold.If I crank it back up it will stall again but if I give it alittle gas it pops back up again. I don't know if this could be an issue in the tune or not.

RBob

iTrader: (1)

I'd keep an eye on the fuel pressure.

RBob.

robertfrank

iTrader: (27)

ok but how do I check to see if I'm in Lean Cruise mode?

RBob

iTrader: (1)

There are a couple of items that can be looked at. On the main WUD display there an a LeanCr indicator.

If looking at a dump log, the Hw column will be Y, the commanded AFR will be high (usually the 15 - 16 to 1 range), and the INT will be locked at 128.

RBob.

RBob

iTrader: (1)

I was looking at your log/bin and noticed the idle was jumpy. Halve the values in these two tables (toolbox, multiply by .5):

SA - Idle Low Compensation
SA - Idle High Compensation

That will help steady the idle down.

If you have a log of the engine stalling send it along.

RBob.

robertfrank

iTrader: (27)

Well now that I'm doing the H/C swap at this moment I found out a couple of reasons for my tuning problems.

1. The Die electric grease under my ignition module disappear and was causing the stalling.

2. Header gaskets had a couple of leaks in them that I didn't notice, plus whoever "welded" in my catback didn't bother to weld up the connection from the Y pipe to the catback, causing another exhaust leak.

So yeah that irritated the ever loving hell out of me. It's amazing what issue you fine when you start taking crap apart.