So you can rev past ~3k rpm when it does this? I know a bad crank sensor in the dizzy can put it into codeless limp mode, injects fuel randomly (can't figure out TDC), and retards timing. I have a P28 with a bad board in it, does this no matter what.
Otherwise it's fairly indicitive of a cold solder joint - heats up a tad, then resistance goes through the roof. But if a pro redid the solder, I don't know. You very well could have a wire SOMEWHERE shorting out, but it very well could be the TPS. My friend diagnosed his turbo ka24 for a month before I mentioned how a bad Honda TPS can cause weird issues.
Last thing would be a strange vac leak, or fuel issue. Replace that fuel pulser thing (cap on the pass. side of fuel rail), that can cause issues, but mostly constant issues.