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MA70-3.0GT, fuel cut is based on a couple factors.... I think I remember injector duty cycle, RPM and airflow being the primary factors although I could be wrong. It doesn't matter much for this situation as duty cycle is largely determined by the airflow signal.

The adjustable bypass screw on the KVAFM isn't a fuel cut device (that would be a side effect though). IMO, It's a crude hack to fix poor idle and low load issues when running in open loop. This is precisely where a fuel controller is the better system as otherwise you're still not managing any imbalances in the mid loads and you've only got one single adjustment to try to balance out a pretty big range. The O2 sensor has a very tight range of operation, isn't referenced under a number of circumstances. It's unreliable as a diagnostic device and I'd prefer not to bet the performance and safety of my engine on it. I don't believe in cheaping out on this stuff especially when doing a better and more trustworthy job/setup doesn't cost that much more.

The Vf circuit is a crap circuit for monitoring fuel trends real time, on a regular basis, especially on any non-stock setup. When I setup a data logging system on a TCCS type Toyota I usually add that to one of the monitored auxiliary inputs but it's yet to provide anything useful which wasn't made more obvious by better devices and much more quickly. A slower responding O2 isn't going to help, you'd be better off dampening the comparator circuit for your Vf meter. Dampening the actual O2 signal is going to affect your entire system. I know a couple of people love Vf but half of those who do still agree that unless the car is bone stock it's worthless and it's definitely no substitute for proper diagnostic devices (namely a wideband).


Ochowdero - If you have tuning experience then you should be fine with any of the 'super p/bs'. Just wire them up and if possible skip wiring in optional functions until you're ready to work with those. With some decent experience under your belt the things that are likely to make things difficult diminish in number quickly. Certain finer things such as tip in enrichments, decay rates and the like and then the functions related to converting to a different type of air flow measurement system should be the only things you'll have to do significant homework on... Even the timing control isn't too bad (but you probably aren't even going to want to use that).