Lambda reading when rowing gears is off

[88a5tq]

Logging while driving through several gears during a hard pull shows some pretty wonky lambda results that err on the rich side. Pulls in each gear separately results in satisfactory lambda readings. Who can relate and is this due to a brief vacuum on my direct port meth injection (using 2 solenoids)? Is this even a problem? I'll post an example log from yesterday later today.
Thanks guys

[88a5tq]

The first gear of the hard pull is normal and all consecutive gears appear rich. I have noticed the same happens if I pull only one gear, and engine brake after, that it goes rich also.

[ChrisAudi80]

What happens is that when you let go of the gas pedal, you suddenly cut off air, but there is still a lot of fuel, so it goes real rich. Also because of the fuel film effect. However, lambda should then go totally lean because the residual fuel has been "sucked" through.
Do you see this? Or only rich? If so, you need to lower VE in the lowest kpa row.

[88a5tq]

Hmmmmm thanks for your reply. I couldn't find an acceptable log on I'll redo it today after work.

From memory, I think it stays rich for several seconds if I continue to engine braking, it slowly would climb to be lean. I'll try your suggestion as well, thanks!

[88a5tq]

Also something to note.. I've never seen anyone mess with the fuel film settings pane in VEMS. I wander if it's already how it should be in the base file I was given and copied for my current tune??

[ChrisAudi80]

Also something to note.. I've never seen anyone mess with the fuel film settings pane in VEMS. I wander if it's already how it should be in the base file I was given and copied for my current tune??

I briefly tried doing something with the fuel film settings, but it just made the lambda values go all over the place. Megasquirt has clearer settings for this. Just leave it. The helpfile is incomprehensible when it comes to this.

[88a5tq]

Lol that's more experience than I have with it at least. Thanks

[ChrisAudi80]

Have you enabled over run fuel cut? If not, try this:
0 kpa, cut above 1800rpm, enable 1600. That should take care of the rich between shifts stuff.
Works a charm.

No, I didn't figure it out myself. Just read a lot and asked some questions on FB.

[88a5tq]

Actually the bizarre part is I do have it enabled LOL

[ChrisAudi80]

Actually the bizarre part is I do have it enabled LOL

That is odd.

You still have this over rich issue?

[88a5tq]

I can't post a pic of my log so I can't even be sure it's a reasonable amount of time to run rich. It seems the same though. My adjustable fuel cut is set to disabled and my settings for over run are 16 kPa and 1600/1300 rpm. Thanks for following along Chris

[ChrisAudi80]

I can't post a pic of my log so I can't even be sure it's a reasonable amount of time to run rich. It seems the same though. My adjustable fuel cut is set to disabled and my settings for over run are 16 kPa and 1600/1300 rpm. Thanks for following along Chris

Do you ever hit 16kpa? Try 0 kpa and the same rpm settings. Watch the injector pulse width go to 0.0ms. Sometimes when you are pushing hard and shifting fast, overrun fuel cut does not have time to engage and so go briefly lean. There's just too much fuel. I see it sometimes too in my logs.

[88a5tq]

Are you high? Reread please

[88a5tq]

Sorry Chris I didn't see your response last year lol. I do hit 16 kPa between gears, yes. Injectors go to zero as well. This engine had 2 cracked pistons too so I'm sure it wasn't behaving normally even when the tune was. Thanks!