O2 sensor and open loop and Vf

[Nick M]

Can you get your hands on a DSO? If you want to do this yourself, you need it.

A DSO is a digital storage oscilliscope, or small hand held scope, to show you voltage over time.

Watch for the sensor cross counting, then you will know quickly if the feedback is working right.

 

[SPD TRP]

I think I will plug in my other ecu and see if things change.

Wayne

 

[SPD TRP]

Swapped ecu's, no change.

Took neo up to -20% on high fuel trims with very little change if any. At idle my Vf is almost 5v but idle afr's are still lean approx. 16.x:1, but as soon as I barely blip the throttle it shoots way effen rich 10.x:1
Still no change with O2 sensor plugged in or not, with either ecu. When O2 is unplugged I do get a CEL.

No other codes stored.

Bypassed the fpu vsv--no change

May have to put it back to stock and start all over.

 

[jetjock]

Well, that's the first post you've made in this thread that actually describes the symptoms. You need to get closed loop working first. Do what I said before. Run the engine at 2500 rpm and check Vf both with the jumper in and out.

 

[SPD TRP]

Well, that's the first post you've made in this thread that actually describes the symptoms. You need to get closed loop working first. Do what I said before. Run the engine at 2500 rpm and check Vf both with the jumper in and out.

I will try this tomorrow.

Thanks

Wayne