Strange S.trim issue on idle

[AJRacing-SA]

Hi guys

Ok, busy tuning this car with kpro4, all is going well besides the idle. Had this problem previously with other cars and had to stay off the 0 degree cam angle in order to get around it. Unfortunately with this vehicle, even though the CAM table is set to 10 degrees, its staying on 0 on idle. Cam angles work perfectly everywhere else.

So basically, get the s.trim spot on for idle, drive around, then all the sudden its either trying to pull ridiculous amount of fuel, or trying to add.

In live tune mode, for example with this log I'm attaching, I let the s.trim go up until it settles to 25% (max I've set it) then at 1:08 I add 1% fuel via live tuning and all the sudden it adds like 25% of fuel according to the inj ms. At this point, you can hear the engine surge from that 1% fuel, and then the s.trim goes down to 3% which I'm happy with. Turn off car, Upload cal, restart, then all the sudden the s.trim is going back up to 25%. Just cannot get the idle dialled in, everything else seems to be fine. Last 2 times I had this problem it was only affecting the 0 degree cam angle. Once I used the 10 for idle, everything worked as it should.

Attached is the calibration and datalogs. Datalog 1 is where I added the 1% fuel at 1:08, 2 is the start up of the 1% fuel added map after upload. The injector ms just seems to jump around and not be consistent with the fuel parameters. Tried to zero out all compensations so it can't be affected by that.

Car is a em2 with k20a2 complete wiring loom, all wiring is good, and the ecu is out my own personal car which doesn't have any issues.

Side note: Why with the AEM30-0300 does it have to read 7's-8's while the sensor is busy warming up... this causes the S.trim to go full retard negative and the car to lean out before it gets the proper reading and then has to add all the fuel back. Would be nice if there was an option that we could tell kpro that a/f is 14:7 for the first 20 seconds or so of startup to avoid this.

[AJRacing-SA]

Just to add, this is on a PRA ecu

[Hondata]

VTC is always 0 at idle and decel.

The wideband has a very slow response, so the initial trim is not the main problem. It could be the sensor, or the placement in the exhaust, or an exhaust leak or lack of current for the o2 heater. If you did not have stock injectors I'd say it could also be dead times.

Can't do much about the warm up reading. Each AEM wideband model operates differently and none of them seem particularly well thought out.

[AJRacing-SA]

Thanks

I think there is a very slight leak on the exhaust which Ill get sorted out tomorrow, but that still doesn't explain how a 1% fuel change can make such a drastic difference to the a/f ratio. This is the 3rd car I've tuned that has done this... this car has an aem, the other two PLX gauges, all placed close to original positions, and all been brand new sensors and gauges. As I've mentioned, while I'm slowly pulling or adding 1% at a time spaced about 2-3 seconds apart, there will be one click that instantly changes the whole sound of the engine, basically like pulling 50% or adding 50% in one change.

This is the part that bothers me... its normally far more progressive when you go lean to rich or vice versa.