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I was wondering if anyone has any experience dealing with idle stability on Subaru's, specifically EJ257's. Ever since I installed an adjustable fuel pressure reg my idle is very sensitive to load changes, such as AC cycling, power steering load and to a lesser degree electrical load. I even get the occasional stall.
I feel confident in my Injector data and MAF calibration so I'm thinking the issue could be resolved in the idle adjustments, I'm just not too sure where to get started.
I can't see why there should be a link between the new reg and your engine all of a sudden becoming sensitive to load changes? I'd be looking at your closed loop trims at idle just to be sure that they are in the ball park. Often I see issues with idle quality when people try to make the engine idle too low but this is usually an issue once you start modifying the engine dramatically, and particularly relevant when larger cams are installed. If you're running an aftermarket ECU then often i find that targeting a little richer than stoich can help stabilise the idle. I normally try for around 0.95 or thereabouts.
Thanks for the reply Andre, after I installed my FPR I set my base fuel pressure then calibrated the latency and scaling. My trims are all < 3% +/-. I did watch the webinar you did on idle adjustment and I think I may have been a bit guilty of trying to target too low of an idle for what my engine was comfortable with. I bumped it up about 75 RPM and that seemed to have a positive effect. I also bumped up the over run threshold a bit to have the injectors resume operation about 100 RPM sooner to see if that helps the clutch in return to idle, I would get the occasional stall in that scenario.