arf ratio at idel

[ony]

how can I ajust the afr ratio at idel , I have got a closed loop idel bin. it needs to be a little richer at idel but the rest of the bin works good, [ smells like the timming is to fast, and the adjusting jets are turned in to far on a carbed engine] don't have a cat, tried setting the timming in the bin back 4 degrees ideled smoother but still smells bad. didn't know if there was something I could change besides the 14.7-1 in the synchronized fuel ratio?

[EagleMark]

Without a CAT it will always smell rich. I don't care how good you are your nose is a horrible AFR gauge.

So that leaves a Wide Band AFR gauge...

The AFR setting or Stoich setting is dependent on fuel. Unless your paying for non ethanol which is 14.7 to 1 AFR? Most fuel is 10% ethanol and 14.13 AFR at Stoich, your narrow band O2 sensor adjusts to Stoich... not 14.7 to 1.

But there is an adjustment for AFR bias at idle based off O2 sensor. It's only a slight adjustment, not real accurate and will only do so much.
"O2 - Idle AFR Bias Value" = Bias used to lower AFR at idle.

[ony]

thanks eagle mark, my idle afr ratio bias at idle is 0.00 in tp I will try 0.50 and see what that does.

[EagleMark]

Was that your V6 bin? I'm used to seeing 109.0 for the V8 as a stock setting.

[ony]

yes its v6, I set it to 100.? it don't smell rich at idle its a to lean smell to me or timming to fast in an old ford smell. I set the open loop afr ratio to 14.4-1 but it stays in closed loop at idle most of the time so I didn't think that would affect it. I been running 14.4-1 in open loop for along time to get rid of the rich smell at idle. lean cruise is still working good went 140 miles [on the high way] the other day seamed to get 20-21.5 mpg an run pretty good just when I stop its got that bad smell. not bad mpgs for a old worn out chevy pickup.

[EagleMark]

That Stoich AFR setting is what's used in Closed Loop.

[ony]

I got to go to the store here in a few minutes I will see if changing the idle bias helps, if it don't I guess I will start dropping scotch in closed loop down,you proble know how many chips I have burned [playing] I get back to work I am going to get a tune on the fly set ups. ever time I change something burn a chip, I think one of my sst 512s is getting worn out have to play with it awhile to get it to program some times.:popcorn:

[RobertISaar]

there could be a couple of reasons for that, usually bad contact on the chip's legs. every once in a while, if i have a PROM that hasn't been installed in anything and attempt to use it, reading/writing to it is a no-go. i end up "polishing" the sides of the legs that make contact with a ZIF socket with a pass or two on each leg with a sharp edge on a knife. VERY little pressure needed, ends up nice and shiny for a couple of months of being uninstalled.

[ony]

that proble what it is, if I put it in my programmer an slide it side to side as I close the lever slowly it usely works,i may need to clean all the little legs. went to the store, now I do have a rich smell at idle not real bad it seams to operate smoother at real low speed, I will drop the bias back to 50.00 an try it out Monday evening if it hot enough here,if I don't data log about the same time of day ever thing changes a lot, for a out side temp change of 70 of the morning an 90 degreez of the evening, I think it the air moisture % that makes my blm change, I notice it changing more when I get on the gravel and dirt roads to the house.been thinking about employing the egr at idle an using the bpw consitn to get it to smell better.

[EagleMark]

As many times as you have burned chips, your legs are probably worn thin? May need a new chip...

EGR at idle is thinking outside the box! Not sure the results are going to be good though?

[RobertISaar]

EGR at idle.... very tricky and slippery slope. it doesn't take much EGR at all to turn a rock-solid idle pretty choppy.

[ony]

I guess that is kindof off the wall thinking, I dropped the % of the egr at 1200 down to 94-95 % it helped with jerking on hot restart as I go across parking lots. the legs on my chips do need cleaned their not corroded but discolored alittle.

[EagleMark]

EGR at idle.... very tricky and slippery slope. it doesn't take much EGR at all to turn a rock-solid idle pretty choppy.With a vacuum operated EGR I don't think it would have the control to even try?

[RobertISaar]

possibly. i'm used to the 3 tower digital EGR, if i manually switch on the small solenoid at an idle, there's a noticable stumble at first, then the IAC and spark catch up to it, and if in closed loop fueling changes too. if the medium solenoid goes on, big stumble, almost never stalls, IAC/spark/fuel and it gets back to the desired idle speed, but noticable lope happens. switch on large solenoid and it can stall the engine if the idle correction stuff isn't VERY well matched. takes a little longer to get this one back to desired speed, and when it does, it sounds like an entirely different cam.



you know, maybe i do want EGR at idle :laugh:

[ony]

on a 747 ecm what is [ egr on low vss] in tuner pro. my bin is set to 0.00 ?

[EagleMark]

I changed the names in the next XDF.

But the VSS on and VSS off are MPH. Most all $42 bins I've seen are all 0.00, meaning MPH is not used as a qualifier. Could be if testing was done? Seems the main qualifier is TPS on and off.

I haven't spent a lot of time in EGR code, but it looks like there's not much room for adjustment, again I think this is because of vacuum operated EGR valve and switch. It's open or not. Not going to be good at idle. It's only compensation and Fueling and spark at RPM and MAP/Vacuum.

[ony]

I was wondering about it, been reading the post where you was testing with it off below 25 mph, I burn a lot of gas driven up this mud an dirt roads [15-20 mph] when I get to the gravel road I can go 30-35 an everthing seams to work pretty good. my try 25mph setting and see if my blms change tomorrow after I data log, should indicate if the mph setting changed the off on egr setting. I cleaned my chip legs two legs was so thin they fell off, I sodered some from a donor chip on them works good, being broke sucks.:laugh:

[EagleMark]

I just have never spent much time EGR tuning, so don't take what I say as accurate. For the most part high performance engine EGR is turned off, stock engines on, conversions either on or off if they have it.

When accelerating from a start and slow MPH well the MPG is going to be lower. That other conversation started because I happened to find some bank 1 to bank 2 fueling correction with EGR on. Then I was surprised it was on during what I consider a load, not high but face it to get a vehicle moving from stop is a load, when up to speed and at cruise well load is a lot less and I could understand how EGR would help MPG.

BLMs should not change when EGR on or off because of the EGR fueling compensation. Going to be hard to trace any gains in MPG at low speeds like we are doing. May be better with the BPW, Injector Duty Cycle or MPG history tables, even then gains or losses are going to be small and hard to track.

Old School still works if you can get data from same section of road repeatedly. Lower TPS and higher MAP during same situation is always a good sign.

So you wore out a chip? That deserves some kind of honor or award! :happy:

With that many changes you may be better off with a ZIF socket in your G2 adapter when you get a new chip.

[ony]

I changed the egr to where it was on all the time once the cts temp was met. the thing idles about normal, Robert was right just a little throttle it gets very chopy till it gets to about 4% throttle then it almost normal for as long as I run it, didn't run it long[ no gas ]. to do this experiment I going to wait till I get an ostrich or tune on the fly set up. I think the egr [ % an correction ] is why its chopy. weather it would benefit any thing I don't know just off the wall thinking ,but its to much tunning with out a fly set up.:laugh:

[ony]

I should have put to much playing.:rockon:

[ony]

I have changed my bin file to apaa, its a syn v6 bin,got a few ??s. what does throttle follower filter coeff for low-med- high vss do? the only time the asyn flag comes on in setting still an I reve it up an let off sitting still, seams like it reves up slower with this bin but it operates a lot smoother and I am not done tunning ve1. the mpg hac shows about the mileage the truck was getting acroding to the speedometer with the awdn bin about 65 mph-60-70-map. I think apaa an apab are both syn bins. ihave modified it some what,:jfj:i for got to ask what air divert does, in the apaa bin the temp is maxed out? on this bin gm or someone else is using mph to enable egr I dint change that part of the bin, egale mark going to have to see if you will employment the esc lean cruise patch on this bin when I get done ajusting it the way I drive, its a sync bin I guess from gm for a 4.3 std trans for some reason I apply the patches an they fail, more than likely it operator eeror,:jfj::laugh: I finaly got that patch to aply to my bin file, the syn bin gets about 2-3 mpgs at under 30 mph vs the asyn bin I was running operates smoother also. will see what happen at highway speed this week. with both patches apllied I come up with 57 bites differents in the bins instead of 55?

[ony]

you may want to move my last post over to the lean cruise post.