Maybe I have a problem but maybe I don't.

SAUJPv3
8D
cammed 383 TPI

Whenever I get off the gas after a happy dose of pedal my WB02 pegs out lean and stays there for longer than i'd like. I burned up my 350 due to running lean. I'm wondering if this is why.
I haven't found where I can change that as of yet.
I'm using TPRT.

Question is: Do I have a problem where I need to enrich my deceleration or is this me just worrying for nothing?

 

You might want to try adding to the VE table in 20-30kpa area at the rpm you are lean. If you are super lean like 20:1...add 4.00 to those cells and see if that helps.

Tuning my 383...I have about 14.7-15.5 max off the throttle just by adjust the VE table.

 

My wideband shows AIR for the longest time while coasting down from highway speeds with the throttle closed. It is called Decel Fuel Cut-Off and Decel Enleanment.

 

I've never understood how that works. Fuel cutoff? How does the engine stay running? I've never experimented with it.

 

Yes, i'm super lean as in 21:1. I'm not comfortable with that.

I changed fuel cutoff decel disable map from 20kpa to 10kpa. If that doesn't work i'll add some to the really low VE cells. Unfortunately I didn't datalog this run so i'll have to do it again. I don't even know if I hit a MAP value of below 20.

 

I disabled DE when I was tuning. Hell, I am always tuning so I guess it is perm disabled. Actually I see a short period of enrichment on WB when I let off gas due to the increased vacuum sucking the wall wetness off the intake tract and then it spikes lean. adding fuel in that lower kpa area helps and should stick as I dont think much BLM learning occurs down there.

Engine stalling may be more common with a manual trans. i dont recall why.

 

Hehe, that's DFCO you're seeing. IT'S NORMAL. Fuel is completely cut off during coast down. It's not even considered lean, it's just pure air and won't hurt a thing. Lean is only dangerous when the load is high. Medium and light load can handle all sorts of lean with no problems, other than drivability.

Decel enleanment is only used during the split seconds that your foot is MOVING in the closed direction. It's supposed to combat the richness provided by stripping the wall of fuel when vacuum increases, and to overcome some MAP sensor lag.

 

So in other words, don't worry about extended "leanness" on coast-down?

 

Correct.
It's exactly as RedNGold explained it.

 

Thank you. One less problem that I have do deal with.