maverick1998

This is baffling me, I'm learning to tune myself and I've done as much research I can, and am working off a base map that was done by a pro tuner before I changed some things (like a new engine). Everything is running pretty well, except when I'm cruise and lift off to let the car slow by engine brake, the car runs rich. Like 10 AFR or so. The AFR was just callibrated, but it seems the car just doesn't know to stop putting in fuel when I lift off. Any idea why this might happen? I'm completely lost. Unable to take a log right now but trying to figure out where to look. All help is appreciated!!!

dleavitt

iTrader: (1)

Turn on overrun fuel cut?

I'd guess it has to do with your VE table, and the vacuum rows not really being tuned (because why would you need to?).

maverick1998

That makes a lot of sense actually, I'd been running with my supercharger and have temporarily taken it off so it makes sense that I've never had to worry about that area before that much before. Thanks for the advice, I'll mess with those and see how it goes

maverick1998

Yup, you solved my problem!!! I knew it was one of those wierd things that I just had no idea what the name was in tunerstudio. Thanks!!!!

SpartanSV

Overrun fuel cut usage is totally fine, but I bet the root cause is your manifold pressure dropping so low it's off the bottom of your VE table.

You should always post your tune and a log of the issue whenever you ask a question like this. With it we can be absolutely certain what the issue is. Without it we're just guessing.

maverick1998

yeah under normal circumstances I would try to post a log but I was an hour and a half from my house with my laptop but unable to post a log like I mentioned in my post, I was just needing a quick fix for my drive home, which the fuel cut provided. I will try to do a proper fix tomorrow by adjusting the tables as you suggested, thanks!