2018 Yaris SE 5MT - T-Sport w/Valvematic!

[CrankyOldMan]

Originally Posted by atomic_hoji

At least if I'm wrong the problem had us both duped?!

Here's a plot from when I had Techstream running on the weekend.. The Fuel Pump duty request was only about 75% (scale labels are goofy) most of the time - only jumped up to about 90% when I jumped on the throttle some. STFT is all over the place, not surprisingly, but does average out to around 0%'ish... sort of... LTFT (not shown, doesn't change much like STFT) was still -30%, but did jump up and down some. Used a reset Utility to clear all the learned values; even though I had the battery disconnected while I was doing wiring repair, the LTFT was still way off. I'm sure a bad learned value isn't helping the cause.

Have queries in to a couple of online places to see what the price new is for a Fuel Pump Control ECU is; will also need the connector, which is ~$10 or so, and hope I have terminals to use with it.. if not, it's time to Hodge Podge Bodge the bugger.. In all honesty, I think proper FPC should help sort out the fuel trim. Was hoping my clever fuel pump bypass had solved the problem, but seems like it will just end up running overly rich and likely have terrible fuel economy if I leave it this way.

Also dropped the exhaust and notched the flange where it was rubbing the body - not perfect, but a dramatic reduction in the nasty vibration when steering left. When I drop it again to weld the repair piece in I'll round out a bit more off the flange and see if I can 'clearance' the tunnel slightly - yes, I mean use a hammer...

-- Adam

What about swapping the fuel pump itself for one that doesn't use PWM? I'm not sure if the previous gen Yaris uses a fixed rate pump or not, but none of the 2ZR-FE swaps have the same fuel problem.