too lean ?

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famous bob

mopar misfit
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Had some really nice weather yesterday, got the fish out and played w/ it for a while . I leaned the fast 2.0 f.inj. down a hair more at cruise and now its popping out the mufflers quite a bit when descelerating, but doesn`t rattle and runs great , DID I GO TOO LEAN ??
Also discovered my rings aren't seated yet.
 
From the little I understand, popping on deceleration is fine, it’s acceleration popping that’s bad.
 
Deceleration will normally pull more fuel in due to the high vacuum of the closed butterflies creating a rich condition that will cause that popping sound.
 
Had some really nice weather yesterday, got the fish out and played w/ it for a while . I leaned the fast 2.0 f.inj. down a hair more at cruise and now its popping out the mufflers quite a bit when descelerating, but doesn`t rattle and runs great , DID I GO TOO LEAN ??
Also discovered my rings aren't seated yet.
Ol' school
What do the plugs look like?
Pic's always help
 
Deceleration will normally pull more fuel in due to the high vacuum of the closed butterflies creating a rich condition that will cause that popping sound.
if you had a carb, yes. I dont think that would apply with EFI. Isnt popping an exhaust leak? Pulling O2 in and igniting whats left in manifolds? Does 2.0 have a "decel cut" feature that allows you to cut fuel on deceleration, like entering negative values in the fuel table? cut it down to 1750 so itll still idle.
 
Deceleration will normally pull more fuel in due to the high vacuum of the closed butterflies creating a rich condition that will cause that popping sound.

Yep on a carbed motor, because some fuel burns in the exhaust.

But this is "fast 2.0 f.inj" :poke::)

Pishta posted while I was typing.
 
LOL, well, yes, sorry, LMAO, I should have said .... “Just thinking out loud....” I’m subscribed ether way since I’d like to do a FI set up later.
 
Bob, how are you measuring adjustments? Do you have an afr gauge or reading plugs or what? I would say if that is the only change you made it’s hard to believe it’s not the cause but one should not effect the other. The fuel map at criuse should absolutely have no effect on the portion of the map on Decel. Maybe a new exhaust leak?
 
Bob, what plug are you using. I remember you were chasing heat range per our chat awhile back
 
I thought one of the big advantages of the new FI units was supposed to be that they are self tuning.

EFI systems don't self tune, they self correct to a pre-programmed tune. That is too complex for the marking guys to say so they call it self tuning. I'm sure that someday we'll get AI enabled EFI systems that can self tune but it might be another 20 years. For an EFI system to self tune it would need to be drive by wire and only a few aftermarket EFI systems are capable of drive by wire.
 
Jus thinking out loud here,
I have heard that when you go too lean, the fuel cannot always find oxygen to react with and just passes thru the cycle unburned.
So;more thinking;
how about changing the the Ais air to base air ratio, to get the throttles open a lil more during decel.
or, if that popping is from the fuel charge still burning when it enters the pipes,then how about adding some advance in the high-vacuum decel mode, to start the fire a lil earlier.
 
Had some really nice weather yesterday, got the fish out and played w/ it for a while . I leaned the fast 2.0 f.inj. down a hair more at cruise and now its popping out the mufflers quite a bit when descelerating, but doesn`t rattle and runs great , DID I GO TOO LEAN ??
Also discovered my rings aren't seated yet.

It would be good to know what A/F you're targeting?

During Decel its not uncommon to turn the injectors off completely, so you really cant go "too lean" during Decel
 
Had some really nice weather yesterday, got the fish out and played w/ it for a while . I leaned the fast 2.0 f.inj. down a hair more at cruise and now its popping out the mufflers quite a bit when descelerating, but doesn`t rattle and runs great , DID I GO TOO LEAN ??
Also discovered my rings aren't seated yet.

Turn the data logger on and go for a drive. Come back and view the data log on your computer. That is what is great about EFI tuning. You just review the drive on the computer and see if it is too lean or too rich or whatever.
 
@AndyF why would a self tuning efi need to be dbw? Can you elaborate a little please.
 
MS (from V2) is 'self tuning' if your a registered owner of tuner studio. IIRC it can plot fuel curves on your driving habits but I dont know how it data logs because that is only in MS3? Speeduino uses tunerstudio also and claims to be able to self tune, so its more of a TunerStudio feature. My Pro-Flow 1 is NOT self tuning as you had to provide Edelbrock your engine parameters so they could burn you a chip, then you had very limited adjustment range (+-10%?) on certain variables like fuel curve. Pro-flow 2 wrote its own 'chip' on the fly with its programming. I think all modern stand alones now have way more adjustablility than the early ones. Even Ford EEC-IV sort of tuned itself with its Mass air design.
 
@AndyF why would a self tuning efi need to be dbw? Can you elaborate a little please.

If a system is really going to self tune then it will need to run simulations in order to figure out what the best AFR is at different conditions. The only way that can happen is if the system is drive by wire. I don't foresee this happening any time soon, if ever. I'd be surprised if the aftermarket ever creates a true self tuning system but who knows, maybe someone will figure it out. The AFR map has to come from somewhere. Today it comes from the tuner's experience. Tuners know how to run open loop tests to see what the engine responds to. EFI systems do not have the ability to do any of this work and they won't until someone adds AI and DBW and maybe other stuff.
 
I've been accused of lots of things but bein too lean ain't one of um.
 
@AndyF, thank you but that does not describe why it “has” to be dbw. I see it working just as well with drive by cable, simply because it would just have to wait for certain driving scenarios and conditions before parameters are set. Kind of like current ob2 diagnostics. For all of the monitors to be “up” and ready certain conditions have to be met. My AEM infinity is the closest I’ve seen to real self tuning. It uses o2 feedback to trim the fuel table and suggest a “new ve”. Although you do have to target certain afrs in different areas of the map.
 
@AndyF, thank you but that does not describe why it “has” to be dbw. I see it working just as well with drive by cable, simply because it would just have to wait for certain driving scenarios and conditions before parameters are set. Kind of like current ob2 diagnostics. For all of the monitors to be “up” and ready certain conditions have to be met. My AEM infinity is the closest I’ve seen to real self tuning. It uses o2 feedback to trim the fuel table and suggest a “new ve”. Although you do have to target certain afrs in different areas of the map.

Thanks for all the replies, a lot of answers are over my head some what tho .
The fast 2.0 is a supposedly self tune set up , but its to get the engine started (fairly rich) and self tunes from there , but has to be leaned down more , from my exp.
I did go from ngk 7`s to ngk 6`s , ( Andy`s suggestion) , which made a big improvement in plug color , and have even thot about 5`s . Have leaned it further , a couple of clicks a couple of times , I have experimented w/ timing a little and have the initial at 21 right now , ran 20 for most of the time , it did seem last summer it was hard to restart w/ the timing at 21. All in is 34 at 2800 right now , have been running 35 all in at 3000 before for the most part , on 93 oct , non cat piss.
I haven't pulled all the plugs just the easy few, most of the time , and haven`t recently . No 7 is directly in line w/ my steering column , and have a hard time getting it back in straight , ''raised port heads.''
Rechecking the plugs is probly my next step , they have looked like their still rich so far . I have been busy w/ other stuff , and don't get to mess w/ it much in cold weather , "did I say , I hate cold weather ?!" . Turning cold again and supposed to snow , cant get up for it when cold -------------

These raised port heads would b kick *** in a B body, but kinda suck in a 68 fastback , would have been trickflows if they would have been out when I was in the market ---------thanks again guys .
 
Bob, do you tune with a laptop or on a handheld?
 
Do you have the ability to data log on the fast 2.0? I have never tuned one. But it might make sense if you can, to run a data log and plug in a laptop to view it and make adjustments. Rinse and repeat.
 
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