dhcernese

80s? 80 what? AFR? Why would anyone configure a sensor that measures over 20? Deceleration has nothing to do with injector sizing. The engine turns into a simple air pump during deceleration, eventually clearing out enough fuel for the sensor to read off it's scale (i.e. lean). How do inectors come into play?

RX Freak

First, I want to say my PLX500 does more or less the same thing. It goes lean when decelerating especially under deceleration where the engine is being turned faster than idle (downhill). I think this make sense. BTW, I don't have an airpump... So I don't think your experience is necessarly related to that.

The question I have for all of you is what should my AFR reading be on the gauge as a function of RMPs (87 TII)? I've been searching on the forum but can't find a straight answer. Thanks in advance.

GTRay

What ECU are you using? If it is only doing it with the lights on then something is being changed somewhere. and if you don't know what's being changed the worst advice you can get is "it's normal... fugetaboudit!"

check the grounds for your ecu and check your wideband. find someone else with a wideband and see if you can verify on their's. I would suggest building a test rig. a small 2" pipe about 24" long with an o2 bung welded in the middle. stick the wideband in the tailpipe and drive like normal. compare the readings. if they react similar then you can be pretty sure that something is happening to alter your fuel delivery when the lights are on.

I never really liked using the decel fuel cut features when i was tuning. it always made throttle tip-in too lean - especailly durring high load throttle transitions. i prefered to reduce the inj. mS value enough to keep tip-in at an acceptable level. you need that little squirt of fuel for crisp throttle response and it can only be there if the injectors are still on.

what are the afrs in your trouble situations when the lights are OFF?

Ray

gafu mazda

i think his main concern by reading this whole thing is more of"the lights being on and causing"whats happening rather than the leaning itself(IMO).Better ground maybe?ECU ground?Same thing happens to me when I turn the lights on,gauge falls back,not to mention when i turn the radio with the amp on,that makes the gauge look like its getting no gas at all,but it is.