Via the EBL am I understanding this correclty?

Open Loop - idle lean limit
While in idle defines the maximum commanded lean AFR limit.

Why then in open loop at ilde to I see the AFR got about what I have it set... It's a 16 and I see the AFR easily go to 18+ and can stay there...

I would think if I set this at 15 she would not go over that setting?
What effect does this setting have on VE table and other IDLE added fuel... or maybe a better question is what settings overide this Open Loop - idle lean limit.

I am struggling with idle tune were the car seems to warm up ok but then every once in a while she will go lean but does come back down... I don't really see major IDLE RPM changes or MAP changes... I am thinking I have a bad ignition problem as I have locked down SA at 20 and that is all I will see change from 18 to 21 from time to time and right when she swings lean?

I am thinking I have something faulty but don't see anything odd like IAT, injector drip, CTS or TPS issues. Even watching the injectors they look fine... checked for exhaust leaks... OK... fuel pressure stable, 100% steady.

Weird air leak? TBI's rebused. X-ram sealed and tested with air hose and spray... leaning to spark issue? Bad plug? Puddling of fuel?

 

If this is happening after the car is warmed up then it's is not open loop giving you trouble, it's closed loop. Try disabling closed loop and see if it changes at all.

 

I agree OL idle is the way to go. I even enrichened my OL/coolant/vac tables a tad to feed it more fuel. I cant go so far as to blame the XRam but at idle I wonder if unequal fuel distribution in top plenum add to the issues.

 

Nope only run open loop, odd thing she actually seems better idle if closed is used and this more happens after warmed up... get more idle fluctuation after warm... I run low idle speed 650 or so... it sounds better... almost again that I feel like a puddling effects... gets gas then starves for gas.. just do not see any injector issues... no drip... fuel pressure steady... I tried to up the PSI a bit to see if that helped it did for idle but I have yet to drive the car and redo the VE learn... I also tried drastic changes to the IAT vs Coolant temp settings with no real change... idle or during warm up... I am thinking with the larger 90 pound injectors that the pods are not high enough to allow th spray to hit the walls just above the blades... I am already running 2 gaskets and I am in the process of having two 1/4 inch alunm gaskets made and use 1 reg gasket on top, I read that seems to be the height needed... I once seen a actual calculation but can't find that... so most say just set idle and then spray just a tad above blades at idle...

I hate to bring this one up agian but my spider sense is telling me the cam is going on a few lobs again... with the high lift of the 1.6 rockers its not as noticable as before with the 1.5's I want to pull the plugs and do a compression test and check the valve settings after running her for about 2000 miles... also want to check the poly locks and the rocker wear pattern... I just feel not a tune issue and leaning more so to a valve / ignition issue.. as I said the swing is real dramatic at idle... goes lean... then seems to run fine for a few minutes or so then goes lean... IAC's are at 0 at idle...

I am running the extreme 262 cam setup and she really pulls off the line this has better low end torque and HP vs the 268. If I find the cam I am scraping the hydrolic flats and going 268 roller... I based most of this motor off of AFR recommend and the

 

Shot in the dark, but sometimes large injectors don't like to function correctly with very short PW's.
I suppose you could lower fuel pressure and increase your fueling values to compensate and see if that changes anything.

 

I follow what your saying but I don't follow PW and what I would need to start adjusting and how based on PSI and PW is changed in the EBL code...

Higher PW is more fuel? milli seconds?

Again to restate there is a real lean spike every so often at idle with the 90's I ran 18 and 25 and the car seems much better at 25psi without playing with any PW settings...

I will re read the PW sticks and EBL stuff its hard to grasp that tho...

 

PW= pulse-width.
Higher number = more fuel.

Maybe I assumed too much. Are you running 8 injectors like a TPI? or are you TBI? Maybe I missed that part.
Sorry.

Could your fuel pickup be sucking in air?

 

No TBI - dual single 2.13 bores with 90lbs injectors dual variable fuel reg with dial lines... this was not a issue with the smaller 80 cop car injectors.... but these injectors have much much more snap and response.. No she has new fuel pump 50psi and strainer and tank liner is fine and clean tank, new fuel filter... thats all good... and I check injectors with a timing light they are fine do not see anything low volts, pattern change or anything when the AFR hits 18 or so... she does go down to 14.6 at idle but, like I said the AFR gauge does go to 18 swings but I don't see any real changes... I will try and data log and post maybe someone will see something... I forgot to log it...

Let me add I follow all the terms and the basics to maybe middle of the road, but its just not clicking how the whole picture of some of the settings come together... its almost like if I give it gas... then she goes back to idle she takes some time to lets say stabalize... then ones that happens she idle perfect... the idle stays pretty steady, 650-675 rpm but the AFR swings to 18 once in a while and she really don't change the idle that much, but you do notice it... if you were just sitting in car not looking at AFR you would never pay it any attention... just the fact its going 18 scares me a bit... I back off IAC fuel adding made the respones of peddle much better...smoother... crisper...

 

Let me add also if I go higher rpm on idle say 750 the issue is not there... I just don't like that higher idle... auto and she goes into gear harder, and at lights have to hold the foot on the break... she runs fine on hot days... keeps the battery volts at a fine setting and don't bounce... I guess maybe I should be asking what other settings other that VE table should I look at... to possible compensate... and why? I feel at what I have things set at she really should not be going this HIGH AFR 18... I don't see why based on EBL settings... what PW settings should I adjust maybe to see if it changes... I played with AFR settings but I have that were I like for a nice good warm up...
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I just thought of this... I have my dual lines going to the TBI's backwards... looking at the TBI schematics it should not make that much of a difference. I guess I could have air bubbles? I have the factory pressure reg's blocked off and when I did that I pulled out the restrictors and polished and ported the whole a little to take off burrs and open up a little when I redid the TBI's... its hard to see the injector spray changing I am sure.. but I don't see anything drastic that is for sure and the patterns for both are much better that the 80 cop car ones and 100% more even as they are a match set... I am going to redo the lines this spring just to be safe. Just have not had time to do it. AEN fittings are so much fun cutting and getting those ends on... LOL

 

It may be combination of factors.
1. large injectors at low pulse width. Solutionn is to connect the VAFPR I see unconnected. Idle SYNCH !!! Change the IAC counts to zero at idle.
2. idle speed not too low but with the Xram plenum I forsee a river of unatomized fuel settling in corner of plenum. That was what I found after removing plenum. Or 4 of 8 cylinders are lean due toRam design constrints. check the plugs to confirm. I had 4 lean and 4 right on.
3. plenum cool. does the issue improve after plenum fully heat soaked?
4. I hate to use word fudge but enrichen the OL fuel tables 5-10%.

what VAC are you seeing in idle? Or what MAP do you idle at? I idle (manual trans) at 825 at 37 MAP(350 CID 224/230@.05 114LSA). I forget what the VAC meter reads. I will guess 17 lbs?

 

Thats just the install pic I run Vacuum via the VARPR, 25psi unplugged, values based on vacuum...

Plugs look OK. a few whiter than others but all good...

Plenium cool??? that should not make it lean should it? But really no major difference does this hot or cold motor... more noticable warm

Vacuum at idle is about 44/45 - I am going to start this weekend and retest... calling for single digits this weekend... make for a good warmup test.

If running 90 lbs injectors should I be changing the PW settings at all or just dial in the BPW and then VE? Voltage more important with larger injectors? Battery volts very stable... 13.1v

I have someones tune with 90lbs injectors but she's a 383 motor I may try it... as I have in the past and it seemed very good... just for compare, it really smoke the tires with the 85cop car injectors... may see whats diff and adjust a bin...

thanks for the replies...

 

Cold plenum.... hhhmmmm The NB02 will see a lean BLM and add fuel to maintain stoich so I guess a cold plenum will not make car run lean. That is CL operation. Now OL operation. No OL feedback. Would a cold plenum cause enleanment. I will guess yes.

Back to my XRam. why would 4 of 8 plugs show noticible leaner than the others. Unfortunately my buddy pulled plugs and mixed them up. some cylinders were getting a lean mix for sure. I blame the plenum.

Vacuum at idle 45? That means MAP 55?

Set the BPW first with out regard to VE. Then work out VE. there is correction for varying batt voltage. I left that stock settings.