Strange problems. Fuel? Timing?

[ra_guy]

For a while now, I've been having some strange issues at idle. The car seems to fluctuate AFRs more than I've seen previously, and the idle sometimes moves around simultaneously (rich - idle up, Lean - idle down between 900 and 1300 rpm), other times it stays rock steady.
This isn't typical idle surge. I'm on SD and have boost leak tested the entire intake tract to 30psi, no issues. ISC is functioning properly. Fuel pressure stays rock steady. STFT is not the cause. TPS is logging properly 0-100. Checking the "ground timing" box in ecmlink causes the idle to fluctuate pretty drastically(nearly stalling then shooting to about 1400rpm) , which I find odd. Base timing is dead on 5*.
Any thoughts on any of this? I'm running out of things to "fix". I'm on an evo 3 ecu currently, but it's essentially the same as the dsm.

*I should add, I was previously on an evo 8 ecu and was having the same issues, among others (namely isc control which link did fix), so it is not an ecu problem.

**PS: There's a video attached, toward the end there's a knocking sound. I don't think this is related, but any ideas? Keeping in mind this engine has ~900 miles on the build. Sounds like it's in the head, but lifters, cams, valves look great "from above".

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[ThunderChild]

it may not be much help, but im thinking you have a harness issue. seems like you have a wire that may be shorted/grounding out, or high resistance through a connector, somehow.

thats my only thought is to test ISC wires to-and-fro the ECU for resistance with a multimeter. two people will be easier to work with.

 

[ra_guy]

Eh, a harness rebuild has been on the to do list, may just have to bump it up to the top. Worth doing anyway.