I'm dropping into open loop and getting 10AFR at idle [screenshot]
Mar 4, 2007, 08:24 PM
#31
Check the fuel pressure regulator and return line. Have you changed the pump recently? If so did you change the filter sock ? Did you change the fuel filter recently, if so maybe a piece of dirt go into the fuel pressure regulator and is intemittently blocking the return line to the tank.
Lastly check the gas cap for pressure release.
Milburn
Lastly check the gas cap for pressure release.
Milburn
Mar 4, 2007, 11:40 PM
#32
Check the fuel pressure regulator and return line. Have you changed the pump recently? If so did you change the filter sock ? Did you change the fuel filter recently, if so maybe a piece of dirt go into the fuel pressure regulator and is intemittently blocking the return line to the tank.
Lastly check the gas cap for pressure release.
Milburn
Lastly check the gas cap for pressure release.
Milburn
Gas cap is on tight...
Any others wanna take a stab at this? Someone mentioned something about a failsafe mode that the car jumps into when something isnt right....all those logs above were done within minutes of each other...
Mar 19, 2007, 12:08 AM
#34
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In response to the original poster 'SophieSleeps':
I am working through the same issue after having installed an intake/MAF pipe (Perrin) as you describe here. Stalling, dropping out of ClosedLoopAFR=14.7 to OpenLoopAFR=~10.4 at cruise, P0300. I will post more as I figure it out. Here are my notes so far:
My car, mods and setup: 2003 Evo8, 3" TBE, MBC (21psi), Perrin MAF pipe and intake. EcuFlash 1.29 (94170008) , EvoScan v.98b, Innovate LC1.
ISSUE 1: Car fails to find idle and stalls often.
I have for the most part cleared up the idle issues (which were HORRIBLE) by rescaling the MAF table to zero out what EvoScan calls 'FuelTrim_High' and playing with the ISCV settings. (I had raised the idle to '~1000' in all tables in an attempt to abate stalling but it didn't appear to make a difference. Nevertheless, I will leave the idle raised to '~1000' until general driveability is improved.)
ISCV settings have had a huge effect on driveability and idle. Adding '+4' to the ISCV AC=OFFDrive settings for the three highest temperatures fixed the 'pull up hard to a stop light and flame out' problem I was having. Also, it seems to leave a stop MUCH better than even before I had the intake put on. Very responsive with much less clutch feathering to launch. I still have one last issue with nearly stalling - when I pull into the garage and put the car into neutral in anticipation of shifting to reverse to back the car into my parking spot, the car drops the revs to about 500rpm and starts surging. It usually recovers on its own or with a touch of the gas pedal. I suspect I need to tweak the ISCV for AC=OFFNeutral some more. Haven't touched the AC=ON settings yet.
After resetting my ECU and logging with the new intake I originally had the following:
FuelTrim_Low: 100
FuelTrim_Mid: 88 (This surprised me.)
FuelTrim_High:115
After scaling the MAF at idle, resetting and logging until it was more or less stable:
FuelTrim_Low: 100
FuelTrim_Mid: 77
FuelTrim_High: 100
I am going to attack the surprisingly RICH cruise trim, FuelTrim_Mid, tomorrow.
Then, the loathesome 'At cruise, switching between ClosedLoopAFR=14.7 to OpenLoopAFR=10.4' problem. My thinking is that the intake has moved 'cruise' into a different part of the closed loop map that runs leaner than 14.7 (~16:1?). Since at 14.7 it is pulling a lot of fuel via FuelTrim_Mid, when it hits this leaner zone, the momentary 'O2FeedbackTrim' demands even less fuel and maxes out. This kicks it to the OpenLoop map or to some map designed to protect against this condition that is hugely rich. I'll know more once I zero the cruise trim.
Anywho, could definitely use ideas for that one - anyone care to share? Has no one without a bunch of crazy mods ever managed to do this? (I don't really want to reinvent the wheel... but I will. Hey, maybe that should be MJ's sig?)
I am working through the same issue after having installed an intake/MAF pipe (Perrin) as you describe here. Stalling, dropping out of ClosedLoopAFR=14.7 to OpenLoopAFR=~10.4 at cruise, P0300. I will post more as I figure it out. Here are my notes so far:
My car, mods and setup: 2003 Evo8, 3" TBE, MBC (21psi), Perrin MAF pipe and intake. EcuFlash 1.29 (94170008) , EvoScan v.98b, Innovate LC1.
ISSUE 1: Car fails to find idle and stalls often.
I have for the most part cleared up the idle issues (which were HORRIBLE) by rescaling the MAF table to zero out what EvoScan calls 'FuelTrim_High' and playing with the ISCV settings. (I had raised the idle to '~1000' in all tables in an attempt to abate stalling but it didn't appear to make a difference. Nevertheless, I will leave the idle raised to '~1000' until general driveability is improved.)
ISCV settings have had a huge effect on driveability and idle. Adding '+4' to the ISCV AC=OFFDrive settings for the three highest temperatures fixed the 'pull up hard to a stop light and flame out' problem I was having. Also, it seems to leave a stop MUCH better than even before I had the intake put on. Very responsive with much less clutch feathering to launch. I still have one last issue with nearly stalling - when I pull into the garage and put the car into neutral in anticipation of shifting to reverse to back the car into my parking spot, the car drops the revs to about 500rpm and starts surging. It usually recovers on its own or with a touch of the gas pedal. I suspect I need to tweak the ISCV for AC=OFFNeutral some more. Haven't touched the AC=ON settings yet.
After resetting my ECU and logging with the new intake I originally had the following:
FuelTrim_Low: 100
FuelTrim_Mid: 88 (This surprised me.)
FuelTrim_High:115
After scaling the MAF at idle, resetting and logging until it was more or less stable:
FuelTrim_Low: 100
FuelTrim_Mid: 77
FuelTrim_High: 100
I am going to attack the surprisingly RICH cruise trim, FuelTrim_Mid, tomorrow.
Then, the loathesome 'At cruise, switching between ClosedLoopAFR=14.7 to OpenLoopAFR=10.4' problem. My thinking is that the intake has moved 'cruise' into a different part of the closed loop map that runs leaner than 14.7 (~16:1?). Since at 14.7 it is pulling a lot of fuel via FuelTrim_Mid, when it hits this leaner zone, the momentary 'O2FeedbackTrim' demands even less fuel and maxes out. This kicks it to the OpenLoop map or to some map designed to protect against this condition that is hugely rich. I'll know more once I zero the cruise trim.
Anywho, could definitely use ideas for that one - anyone care to share? Has no one without a bunch of crazy mods ever managed to do this? (I don't really want to reinvent the wheel... but I will. Hey, maybe that should be MJ's sig?)
Mar 19, 2007, 12:15 AM
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(Aside: that comment about MJ's sig was meant as a compliment. I reread it and realized that might not be clear. Also, thanks for making the map tracer available at aktivematrix!!)
Mar 19, 2007, 10:48 AM
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The 'AirVol' column in EvoScan has always been spurious and thus ignored. I shoud probably look and see what it is intending to measure. The 'AirFlow' column seems to be as expected. The very low wideband readings and very low timing numbers under very low load and TPS have me believing this condition is referring to an undocumented table or setting. Perhaps a 'limp home' mode.
Apr 8, 2007, 03:39 PM
#38
i have same issue when i start car it idles OK then i press accelerator pedal i goes in open loop then i release gas pedal and car drops the revs to about 500rpm and starts surging with AFR about 10 and lower
DID SOMEBODY FOUND SOLUTION FOR THIS PROBLEM??
DID SOMEBODY FOUND SOLUTION FOR THIS PROBLEM??
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sterlinge (Oct 8, 2017)
Apr 8, 2007, 05:03 PM
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Read my previous post for things I've tried. (Experiment at your own risk, of course, as I am hardly an expert.)
The 500rpm 'too rich' flame out is possibly caused by a 'too lean' transition from closed to open loop. The car compensates for the perceived lean condition by pouring in a lot of fuel which the car can't use.
I richened up the transition area (about a half point so far) to keep it from going way lean and responding by dumping huge quantities of fuel in and this seems to have eliminated this problem so far. I need to cruise and log some more at different load/rpm on different days to be sure. It is a time consuming process and the car seems to change a lot after 20 minutes of cruise so the drives are tedious.
The funny thing is it appears to make your cruise fuel trim swing the wrong way as it senses all the excess fuel you are puking out at 10:1. It pulls the trim back, you get leaner transitions, it dumps more fuel in to adjust and so on... I added some fuel to the tip-in area and reset my ECU. (My cruise trim appeared to be in the wrong direction making the problem worse and confusing the h*ll out of me.) I now have numbers for trims that I expected to see in the beginning, namely, fuel ADDED at idle and cruise.
I undid my MAF scaling while I sorted this out to eliminate variables. Also, adding a few points across the board (+7 from stock) to my ISCV settings greatly improved my idle stability (reminder: I have an intake). I still have idle @~1000.
Your results may vary. Post anything interesting back to this thread.
The 500rpm 'too rich' flame out is possibly caused by a 'too lean' transition from closed to open loop. The car compensates for the perceived lean condition by pouring in a lot of fuel which the car can't use.
I richened up the transition area (about a half point so far) to keep it from going way lean and responding by dumping huge quantities of fuel in and this seems to have eliminated this problem so far. I need to cruise and log some more at different load/rpm on different days to be sure. It is a time consuming process and the car seems to change a lot after 20 minutes of cruise so the drives are tedious.
The funny thing is it appears to make your cruise fuel trim swing the wrong way as it senses all the excess fuel you are puking out at 10:1. It pulls the trim back, you get leaner transitions, it dumps more fuel in to adjust and so on... I added some fuel to the tip-in area and reset my ECU. (My cruise trim appeared to be in the wrong direction making the problem worse and confusing the h*ll out of me.) I now have numbers for trims that I expected to see in the beginning, namely, fuel ADDED at idle and cruise.
I undid my MAF scaling while I sorted this out to eliminate variables. Also, adding a few points across the board (+7 from stock) to my ISCV settings greatly improved my idle stability (reminder: I have an intake). I still have idle @~1000.
Your results may vary. Post anything interesting back to this thread.
Apr 9, 2007, 03:43 AM
#40
What i think i could probably increase my scaling number and then play with latency values. It might solve problem.
But i don't know if it is right thing to do because my inj PTE680(2.186 1.413 0.957 0.687 0.486 0.349)they were supplied with latency values from factory (so i don't know should i touch it??)
But these values for 4g63 i have 2.4 stroker so i don't really know if i should play with latency??
PS thanks for help NOGI i'll try it tonight
But i don't know if it is right thing to do because my inj PTE680(2.186 1.413 0.957 0.687 0.486 0.349)they were supplied with latency values from factory (so i don't know should i touch it??)
But these values for 4g63 i have 2.4 stroker so i don't really know if i should play with latency??
PS thanks for help NOGI i'll try it tonight
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