Throttle Pump?
 

Is it considered normal when going from light throttle (20%) to WOT (100%) to have a brief lean period? Say 14Afr then quickly diving to the 11 or whatever afr that has been determined.

I have great throttle response and have only slightly played with the throttle pump, sustain and increase. Perhaps I am over worrying a problem that may in fact not be a problem. What are others seeing when going WOT? Thanks

-Steven

Yes, split-second lean doesn't hurt anything.
We noticed that on a narrow-band AFR meter.
If you try to adjust fuel so there is no dip, the engine feel like shit.


-Ted

I knew you'd reply. Thanks. I pretty much figured that, I just wanted a little experience from someone. Currently response is great, but it does lean for a brief second. Thanks again.

Yes this is normal and the throttle pump can eliminate much of it, however its a physical condition that is hard to compensate for. When you crack open the TB the rush of air (especially on turbo cars) forces the fuel against the manifolds to some degree, so the Throttle pump helps to compensate for that burst of air. You can also lower your Throttle pump threshold to say 2 or 3% this will cause the throttle pump to activate sooner. Be sure your TPS is calibrated.