Mcfly94 Posted March 9, 2022 Report Share Posted March 9, 2022 Hi just wondering if a correctly configured gear range sensor in the software can be used in the Idle Air Functionality? I can confirm the ECU correctly reads gear, I need to add a neutral park step for cold idle, I've got the cold idle pretty dialled in with the car parked but when cold the change to reverse and resulting load causes the rpm to drop 300/400 and stall. It also struggles to catch the stall but if it does it oscillates In rpm heavily for abit before it clears it self. Curious does the step add once out of park neutral or add when in park or neutral? i.e 40% base 5% neutral park step Would the duty cycle be 45% in park/neutral or in gear? Quote Link to comment Share on other sites More sharing options...
koracing Posted March 9, 2022 Report Share Posted March 9, 2022 Between enabling the pullup resistor and saying if Neutral/Park is active low or high, you can change which way the active state works in the software. You should need more idle duty cycle in gear than you would in Neutral/Park. That trim only adds 0-25%, and can't subtract it, so you should have it active while in gear (which seems counter-intuitive to the name of the trim). FWIW You will want to try it and see how the car reacts, however, because I wasn't able to get enough range of adjustment on an old 69 Dodge dart with a A904 automatic using that trim. In addition to that in that application, the only way I got this to work reliably was with idle set to open loop as the closed loop would take the trim amount away after a bit and cause idle to dip or go over (can't remember which) when changing state back and forth. I ended up just doing a 3D idle table with coolant temp on one axis and park/neutral on another axis (0 and 1 for on or off) with two rows for idle duty in gear and idle duty in neutral/park. Idle ignition trim handled small adjustments fine to make the idle stable even with fixed idle valve duty. Mcfly94 1 Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 9, 2022 Report Share Posted March 9, 2022 For the neutral/park step you need to use the digital input "Neutral/Park", most auto trans have a specific switch for this (used for starter lockout also). If you are only using the Analog input "Gear position Sensor" the neutral/park step is not linked to that. Mcfly94 1 Quote Link to comment Share on other sites More sharing options...
Mcfly94 Posted March 10, 2022 Author Report Share Posted March 10, 2022 Thanks guys I think I could probably set up a virtual aux off the gear sensor to have 3d duty table for park neutral and the drive gears? Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 10, 2022 Report Share Posted March 10, 2022 You can but probably dont even need a virtual aux. You could just put "gear" directly on the table. Mcfly94 1 Quote Link to comment Share on other sites More sharing options...
Mcfly94 Posted March 10, 2022 Author Report Share Posted March 10, 2022 Sweet I'll give it a look! Quote Link to comment Share on other sites More sharing options...
Mcfly94 Posted March 10, 2022 Author Report Share Posted March 10, 2022 Thanks Adam definitely setup what I wanted, now I should be able to fine tune the gear step I did have the in gear duty cycle only about 4/5% increase, enough to stop the stall but not enough to retain a somewhat smooth idle, going to try a little more and see how it treats me. Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 10, 2022 Report Share Posted March 10, 2022 You could possibly do something similar with the idle ign table at the same time, give it say 5deg more advance all over when in gear. The trouble with idle valve only is you dont see the full increase in torque from the extra air until a few engine cycles later. Using advance you can instantly increase the torque on the very next cylinder to fire. Mcfly94 1 Quote Link to comment Share on other sites More sharing options...
Mcfly94 Posted March 10, 2022 Author Report Share Posted March 10, 2022 Like this> Wonder if ill be negatively impacting the tune without ECT as a factor in play Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 10, 2022 Report Share Posted March 10, 2022 Yeah that is what I was suggesting. It will be fine without ECT as the idle valve can take care of the cold fast idle. Typically I only have ECT on the idle ign table if there is no idle valve. Mcfly94 1 Quote Link to comment Share on other sites More sharing options...
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