hugemikeyd Posted June 22, 2023 Report Share Posted June 22, 2023 Hello, I have an 88 RX7 NA that I am in the middle of converting to Turbo, I am running the car with the Turbo intake for now so I can tune the NA regions: 6 port NA block Turbo II intake manifold with an air intake by the battery box NA exhaust manifold without the heat shield (i think this is really heating up the intake...) MonsoonX I have been trying to street tune it and for the most part it runs well once warmed up, but once the under hood temps start to pick up and my IATs reach 130F (54C), the car does not want to idle and will just stall out. Looking at the date, it seems as if the A/F mixture is going rich as things heat up, so maybe I need to adjust my Charge Air Temp Approx table some more. All other Fuel Corrections are turned off at the moment. Have a look around 25:08 where i am trying to keep the car alive at idle when the IATs are hot, you can see the stall. Any leads or help is greatly appreciated! Links: Intake Tune Log Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 22, 2023 Report Share Posted June 22, 2023 Your idle speed control isnt even working as your MAP is above the MAP lockout. So attached is your cal with some changes to idle speed control settings, and I also flattened out the fuel table around the idle area as it was fairly messy around there. Do a new log with these changes so we can tell if it is a fuel issue or other. You may need to adjust the idle base position table since I have lowered the idle timing in this cal. S4 RX-7 6 Port Turbo 2023-06-21 isc fixes.pclx Quote Link to comment Share on other sites More sharing options...
hugemikeyd Posted June 22, 2023 Author Report Share Posted June 22, 2023 Went for a drive this morning, ambient temps were about 10F lower than yesterday, so i stopped a few times and let it idle to get hot. It never stalled but did have some trouble staying alive at the very end. I have been relying on the Mixture Map feature a lot to adjust the fueling as i drive but i never applied a smoothing afterwards, was that one of my issues? Also, for the idle i had targeted 14deg +/- 5deg, since 14 was what i have in the idle regions of my ignition map, I see that you have dropped that down to 5deg and the swing is -5deg to 25deg, does that just give the idle control more leeway? I also saw the MAP lockout go up from 50kpa to 80kpa, i guess when the engine gets hot it pulls less vacuum? Really appreciate the help, I have learned a lot reading these forums Log Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 23, 2023 Report Share Posted June 23, 2023 21 hours ago, hugemikeyd said: but did have some trouble staying alive at the very end. Is there an example of this in the log? I see you have a bit of undershoot on idle entry but that is mostly because you haven't adjusted the base position table which I suggested you would have to do. It looks like your hot base position needs to be about 41%. I dont see it struggling to stay alive though? 21 hours ago, hugemikeyd said: but i never applied a smoothing afterwards, was that one of my issues? Smoothing is not really the issue, more so just need to pay more attention to what the numbers mean. For example your -8psi, 750RPM cell had a value of 41.6 in it, the cell right next to that at -8psi, 500RPM had a value of 69.6 in it, that means you are dumping in 70% extra fuel for a 250RPM dip in engine speed. 21 hours ago, hugemikeyd said: Also, for the idle i had targeted 14deg +/- 5deg, since 14 was what i have in the idle regions of my ignition map, I see that you have dropped that down to 5deg and the swing is -5deg to 25deg, does that just give the idle control more leeway? You control engine speed by adjusting the torque, airflow (idle valve) is a relatively slow way to manipulate torque, ignition advance is almost instant. But you had a target of 15deg and were only allowing 3deg adjustment either side of that so the ecu didnt have a lot of authority to manipulate torque . Peak torque is somewhere around 25deg for a rotary so the further we are away from that at normal stable idle, the more torque we have in reserve when it is quickly needed for idle adjustment, near stall events etc. Quote Link to comment Share on other sites More sharing options...
hugemikeyd Posted June 23, 2023 Author Report Share Posted June 23, 2023 4 hours ago, Adamw said: Is there an example of this in the log? the engine speed was ~500rpm, if i just have to play with the idle base position, i will make those adjustments 4 hours ago, Adamw said: Smoothing is not really the issue, more so just need to pay more attention to what the numbers mean that makes sense, this is what i meant by smoothing. the map can't jump all over the place, it needs to be smooth and make sense not just in the active cell, but the ones that surround so that fueling doesn't become erratic. i was relying on the mixture map too much and not interpolating the changes to the surrounding cells, i will make sure to do that from now on, pretty silly to have to say that out loud now that i have said it... 4 hours ago, Adamw said: Peak torque is somewhere around 25deg I actually didn't know that, makes a lot of sense why you would want that to be the max ignition for idle! I very much appreciate you following up Quote Link to comment Share on other sites More sharing options...
kaptainballistik Posted June 26, 2023 Report Share Posted June 26, 2023 You aren't using the Factory water temp sensor are you? Quote Link to comment Share on other sites More sharing options...
hugemikeyd Posted July 2, 2023 Author Report Share Posted July 2, 2023 I am not using the factory sensors for the Link at all, CLT is a Delphi TS10076 Quote Link to comment Share on other sites More sharing options...
kaptainballistik Posted July 3, 2023 Report Share Posted July 3, 2023 10 hours ago, hugemikeyd said: I am not using the factory sensors for the Link at all, CLT is a Delphi TS10076 Good, because thats EXACTLY the antic you get from a Faulty factory ECU water temp sensor!!! Quote Link to comment Share on other sites More sharing options...
hugemikeyd Posted July 17, 2023 Author Report Share Posted July 17, 2023 I've been tuning the car more and was able to get things a bit better, but the car will still stall when hot and dropping back down to idle. I can see the RPMs drop to 500-600 and the ECU is unable to catch it before it's too late. This is more pronounced when hot, when the car is warming up or is initially at operating temp, the RPMs still drop, but the ECU can catch it. I have tried to adjust things to make it better, but nothing has worked so far. What else can i try? Tune and Log Quote Link to comment Share on other sites More sharing options...
koracing Posted July 17, 2023 Report Share Posted July 17, 2023 Increase base throttle position usually helps a lot for that scenario as idle speed will be less dependent on the ecu to be correct. Your link is broken and just links back to this post lol. Quote Link to comment Share on other sites More sharing options...
hugemikeyd Posted July 17, 2023 Author Report Share Posted July 17, 2023 Link updated, no idea how that happened... are you saying that my throttle is too closed at rest? I can try and crack it a little bit to see if that helps. When i first got the car running it would idle at 2.5k, so i closed it a good amount to get it back down to a normal idle Quote Link to comment Share on other sites More sharing options...
koracing Posted July 17, 2023 Report Share Posted July 17, 2023 Yes that's what I'm saying. Turn idle control all the way down or off and set base throttle position so the car idles at about 50 rpm below target. Then re-enable idle control and retune idle. Alternatively increase throttle base with idle control on and get it to where it only needs about 20% IAC to idle properly fully warmed up. Quote Link to comment Share on other sites More sharing options...
hugemikeyd Posted July 17, 2023 Author Report Share Posted July 17, 2023 I will work on that. If you take a look at the log, it keeps getting richer and richer as the Charge Temp increases, do i still need to adjust my Charge Temp Approx table to help compensate for that or something else? Maybe the closed throttle plate is what is making it run richer? Quote Link to comment Share on other sites More sharing options...
hugemikeyd Posted July 20, 2023 Author Report Share Posted July 20, 2023 I was able to make the static throttle body adjustable so I am able to make the necessary adjustments. However, for any RX7 owners out there using an aftermarket intake, make sure that your BAC valve is not just open to the engine bay like mine. If it is, it will suck in very hot air rather than colder air coming in from the intake. Also, this means that the Intake Air Temp is reading lower than what the BAC is pulling into the intake before it gets combusted. That very reason is probably why I was having an issue with getting the Charge Temp Approx table correct, it really depended on the temperature within the engine bay which is not measured, as opposed to Intake Air Temp and Engine Coolant Temp. I will play with the adjustment to get a stable idle with the Idle Control set to 0% at temp and report back what i see Quote Link to comment Share on other sites More sharing options...
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