Stalling when hot outside
#1
Stalling when hot outside
I am having a strange issue I cant seem to find a solution for. My car has been running and idling great but when it got hot out i found an issue with warm start up. If I drive around and get the car to operating temps, maybe a bit more, then I turn it off and let it sit in the sun for 5-10 minutes when I go to start it up again the car starts then stalls. Sometimes it will start and then if i rev it the rpms will drop down and stall.
If i give it enough gas to not let it stall and drive around a bit the issue goes away.
Any idea what this could be?
Sorry for all the threads recently, I just want to keep these issues seperate
If i give it enough gas to not let it stall and drive around a bit the issue goes away.
Any idea what this could be?
Sorry for all the threads recently, I just want to keep these issues seperate
#3
Cpt. Slow
iTrader: (25)
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,178
Total Cats: 1,129
Heat soaked IAT, pretty common. After you warm up the engine then shut it off, that heat dissipates off and the sensor literally soaks it up. When you start the car, the sensor now reads crazy temps, like 100-150f. But the air going in is actually cooler (more o2), say 80f. The MS injects enough fuel for 150f air, but starts running lean until you drive around, letting the air cool the sensor off to a more accurate reading.
Try changing your MAT air density table under Basic/Load settings, to inject more fuel at higher temps. Doesn't need much, just enough to run properly until it cools itself off.
Try changing your MAT air density table under Basic/Load settings, to inject more fuel at higher temps. Doesn't need much, just enough to run properly until it cools itself off.
#4
Heat soaked IAT, pretty common. After you warm up the engine then shut it off, that heat dissipates off and the sensor literally soaks it up. When you start the car, the sensor now reads crazy temps, like 100-150f. But the air going in is actually cooler (more o2), say 80f. The MS injects enough fuel for 150f air, but starts running lean until you drive around, letting the air cool the sensor off to a more accurate reading.
Try changing your MAT air density table under Basic/Load settings, to inject more fuel at higher temps. Doesn't need much, just enough to run properly until it cools itself off.
Try changing your MAT air density table under Basic/Load settings, to inject more fuel at higher temps. Doesn't need much, just enough to run properly until it cools itself off.
#5
This is textbook lean hot restart like I said in your last thread. It's a combination of the injector dead time changing because they've just sat on the hot head for 15 minutes with no cooling fuel flow, the fuel density changing because it's also sitting in the hot bay, and a itty bitty tiny bit to do with the IAT. Log it, I'd bet a nickel it's not pulling anywhere near as much fuel as you expect.
You can tune this with ASE, increase ASE for hot coolant temps and increase the ASE taper time. Using newer injectors helps a lot, too.
You can tune this with ASE, increase ASE for hot coolant temps and increase the ASE taper time. Using newer injectors helps a lot, too.
#6
This is textbook lean hot restart like I said in your last thread. It's a combination of the injector dead time changing because they've just sat on the hot head for 15 minutes with no cooling fuel flow, the fuel density changing because it's also sitting in the hot bay, and a itty bitty tiny bit to do with the IAT. Log it, I'd bet a nickel it's not pulling anywhere near as much fuel as you expect.
You can tune this with ASE, increase ASE for hot coolant temps and increase the ASE taper time. Using newer injectors helps a lot, too.
You can tune this with ASE, increase ASE for hot coolant temps and increase the ASE taper time. Using newer injectors helps a lot, too.
@curly is it ok to flatten the curve like this?
#7
You are not hitting any air temperature related fueling changes in the log you posted.
You need to tune, you are tanking to 10.7 AFR. You are stalling from too much fuel, not too little. Your VE goes from 50 to 100 something, and the AFR follows fine.
Zeroing the air correction table isn't going to do anything but have you running rich when it's hot out.
You need to tune, you are tanking to 10.7 AFR. You are stalling from too much fuel, not too little. Your VE goes from 50 to 100 something, and the AFR follows fine.
Zeroing the air correction table isn't going to do anything but have you running rich when it's hot out.
#8
You are not hitting any air temperature related fueling changes in the log you posted.
You need to tune, you are tanking to 10.7 AFR. You are stalling from too much fuel, not too little. Your VE goes from 50 to 100 something, and the AFR follows fine.
Zeroing the air correction table isn't going to do anything but have you running rich when it's hot out.
You need to tune, you are tanking to 10.7 AFR. You are stalling from too much fuel, not too little. Your VE goes from 50 to 100 something, and the AFR follows fine.
Zeroing the air correction table isn't going to do anything but have you running rich when it's hot out.
#9
Do you understand the premise of speed density tuning, because I'm not sure you do. If you don't, how can I even begin to explain things to you? Would you like me to rewrite the entire manual? The problems you are having are step one tuning problems, and I'm a bit insulted when I have to explain such simple stuff. When you say you've been reading, reading what exactly?
I don't know exactly what is going on with your car, but from that one log you've posted it's evident the car is nowhere near ready for driving. It idles 12.6, and your VE numbers are all over the place. It tanks rich, then lean because your fuel table is potatoes. You can't expect that to work at low load and low rpm on a cold motor.
Mega Miata
Read that, make sure you notice the "older posts" button at the bottom, go all the way to the beginning.
I don't know exactly what is going on with your car, but from that one log you've posted it's evident the car is nowhere near ready for driving. It idles 12.6, and your VE numbers are all over the place. It tanks rich, then lean because your fuel table is potatoes. You can't expect that to work at low load and low rpm on a cold motor.
Mega Miata
Read that, make sure you notice the "older posts" button at the bottom, go all the way to the beginning.
#10
Cpt. Slow
iTrader: (25)
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,178
Total Cats: 1,129
^^Chill bro, we all start somewhere.
OP, I made a quite comment minutes after leaving the dyno, dialing in a MSM, well, until it blew a turbo. I may have looked passed your poor base tune.
I'd touch nothing except for fuel, and get that dialed in. Then if you notice a big difference in AFRs on a hot day vs. a cold one, that's when you might change the MAT density table. Notice in the comments however, that this curve is based of the ideal gas law. The big word being LAW. It's physics.
However, at some MATs you'll hopefully never see, like 140+, it's probably ok to lessen that taper (again, after fuel table is nailed), in order for it to maintain idle until it regulates it's MAT.
OP, I made a quite comment minutes after leaving the dyno, dialing in a MSM, well, until it blew a turbo. I may have looked passed your poor base tune.
I'd touch nothing except for fuel, and get that dialed in. Then if you notice a big difference in AFRs on a hot day vs. a cold one, that's when you might change the MAT density table. Notice in the comments however, that this curve is based of the ideal gas law. The big word being LAW. It's physics.
However, at some MATs you'll hopefully never see, like 140+, it's probably ok to lessen that taper (again, after fuel table is nailed), in order for it to maintain idle until it regulates it's MAT.
#11
^^Chill bro, we all start somewhere.
OP, I made a quite comment minutes after leaving the dyno, dialing in a MSM, well, until it blew a turbo. I may have looked passed your poor base tune.
I'd touch nothing except for fuel, and get that dialed in. Then if you notice a big difference in AFRs on a hot day vs. a cold one, that's when you might change the MAT density table. Notice in the comments however, that this curve is based of the ideal gas law. The big word being LAW. It's physics.
However, at some MATs you'll hopefully never see, like 140+, it's probably ok to lessen that taper (again, after fuel table is nailed), in order for it to maintain idle until it regulates it's MAT.
OP, I made a quite comment minutes after leaving the dyno, dialing in a MSM, well, until it blew a turbo. I may have looked passed your poor base tune.
I'd touch nothing except for fuel, and get that dialed in. Then if you notice a big difference in AFRs on a hot day vs. a cold one, that's when you might change the MAT density table. Notice in the comments however, that this curve is based of the ideal gas law. The big word being LAW. It's physics.
However, at some MATs you'll hopefully never see, like 140+, it's probably ok to lessen that taper (again, after fuel table is nailed), in order for it to maintain idle until it regulates it's MAT.
Is it possible that I have a mechanical issue that is just rearing its ugly head when it gets hot out or is it most likely something in my tables I am missing. Thanks for understanding that this is completely new to me and I am looking into everything you guys tell me so I can keep learning.
#12
Cpt. Slow
iTrader: (25)
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,178
Total Cats: 1,129
Well, personally I'd like 11-12 when under full boost, anything below ~11.3-4 should be avoided. Cruise should be in the 15s, but that's really getting picky for good mileage, not a necessity.
I don't think it's a mechanical issue, just needs some more tuning.
I don't think it's a mechanical issue, just needs some more tuning.
#13
The hard thing for me is right now there is no issue so its hard to learn what I need to fix.
#14
You bought an identical copy of what you already have, DIY is not going to tune your car for you, basemaps are NOT for driving the car on, and that was a huge waste of money. You will be miserable till you learn to tune street manners yourself.
We all have to start somewhere, but we all have to start.
Again, I would bet a nickel you are wasting so much time and money because you can't be bothered to sit and read how the MS2 actually works.
We all have to start somewhere, but we all have to start.
Again, I would bet a nickel you are wasting so much time and money because you can't be bothered to sit and read how the MS2 actually works.
#16
I am running open-loop now and I think i may have found out my issue. My AC is pretty much always running (on or off) and I just noticed that it seems my AC fan is controlled by the WLED port and not my cooling fan, it was set to 92 and I noticed my AC would start working at 92 degrees and not the cooling fan. The car cooled down a bit (below 92) and the ac was blowing hot, I dropped the WLED threshhold to 70 and bam the AC blew cold and my idle dropped to 700. Am I going crazy?
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