Patch request discussion: rev-down maf clamp (stalling issue)
Aug 11, 2011, 05:58 PM
#31
Some people seem to be having the issue because of the ISCV tables. If you are using a Tephra version ROM that isn't your stock ROM, maybe try matching the ISCV tables back up (or at least comparing them)...all of the tables that are mentioned in mrfred ISCV disassembly.
Also, just for mention, if it is 9694-->9653, back when I coverted way back when, the ISCV tables weren't found yet. But, idle was a known issue for that conversion where the BISS needed to be set properly. Not sure if you tried that or not.
Last edited by l2r99gst; Aug 11, 2011 at 06:01 PM.
Aug 12, 2011, 07:57 AM
#32
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Post a log of your car stumbling at idle during decel. DataLog the following: Timing, Airflow HZ, RPM and Load. I will see if I can't help out. The key is to find the engine load your car is seeing during the 'stumble'. It will most likely be between 60-90 load, around 500-1000 rpm.
-Jamie
-Jamie
Which is the MAIN reason why this is so irritating...... I'm on a stock rom but having the same **** issue.
Aug 12, 2011, 08:21 AM
#33
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What was your stock ROM and what TephraRom? Is it 96940011 and 96530006?
Some people seem to be having the issue because of the ISCV tables. If you are using a Tephra version ROM that isn't your stock ROM, maybe try matching the ISCV tables back up (or at least comparing them)...all of the tables that are mentioned in mrfred ISCV disassembly.
Also, just for mention, if it is 9694-->9653, back when I coverted way back when, the ISCV tables weren't found yet. But, idle was a known issue for that conversion where the BISS needed to be set properly. Not sure if you tried that or not.
Some people seem to be having the issue because of the ISCV tables. If you are using a Tephra version ROM that isn't your stock ROM, maybe try matching the ISCV tables back up (or at least comparing them)...all of the tables that are mentioned in mrfred ISCV disassembly.
Also, just for mention, if it is 9694-->9653, back when I coverted way back when, the ISCV tables weren't found yet. But, idle was a known issue for that conversion where the BISS needed to be set properly. Not sure if you tried that or not.
Aug 12, 2011, 08:25 AM
#34
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I experimented with 96530706 and 94170715 for months. I tried everything from BISS adjustment to playing with ISCV tables. Btw most of the ISCV tables are mislabeled in 96940011 and 94170015. Mr Fred figured it all out for 9653 and for the IX rom. I ended up switching back to 96940011 with the same tune as my Tephra rom and my idle was back to being perfect. The part throttle then clutch in stumble was both aggravating and embarrassing (stalling while pulling into a car meet).
The only other thing I notice is now, when I turn on my lights, my idle drops about 100rpm, and if I turn on my second set of low lights, it drops another 100rpm. Could this be latency issues on the injectors, or is this the norm?
Aug 12, 2011, 11:15 AM
#37
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You can't pressure test by driving the car and looking at the boost gauge. Pressure testing involves removing the intake pipe and capping the turbo inlet with a pressure tester. You then use compressed air to pressure the entire intake tract while listening for leaks. Leaks are common on Evos.
Aug 12, 2011, 11:53 AM
#38
I experimented with 96530706 and 94170715 for months. I tried everything from BISS adjustment to playing with ISCV tables. Btw most of the ISCV tables are mislabeled in 96940011 and 94170015. Mr Fred figured it all out for 9653 and for the IX rom. I ended up switching back to 96940011 with the same tune as my Tephra rom and my idle was back to being perfect. The part throttle then clutch in stumble was both aggravating and embarrassing (stalling while pulling into a car meet).
Aug 12, 2011, 12:22 PM
#39
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I meant to say that the older ISCV AC on, AC off, neutral and drive tables were wrong. The disassembly tables are the correct ones. I have the 9694 tables. The 9417 tables are incomplete.
Aug 13, 2011, 02:04 PM
#40
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You can't pressure test by driving the car and looking at the boost gauge. Pressure testing involves removing the intake pipe and capping the turbo inlet with a pressure tester. You then use compressed air to pressure the entire intake tract while listening for leaks. Leaks are common on Evos.
I meant I have done a boost leak test with the little device I made off of a how to here. No leaks. Just meant my car is holding boost strong.
Aug 28, 2011, 03:39 AM
#41
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just go to iscv demand target idle trim and bump up the the percentages of the first 4 rows to 1.6 % or whatever that works for you.Then you should bump up the last two cells of the iscv demand cts adder table, you can find which one is ac off neutral and drive they are listed in the iscv disassembly thread ( the old iscv demand tables under idle are wrong so you should use the new iscv control tables) And you should log iscv demand in evoscan and see how much your iscv demand is at normal idle and how much it is increasing to compensate for the rpm drop and to get it back to idle normal again and at idle your isc steps should be between 2-25 so play with the iscv demand cts adder tables to get it to idle between 2-25 mine is about 19 at neutral with ac off. That's what worked for me i am using the 96530706 rom and i have kelford 272's and i was experiencing idle drop and the car would stall when i would get to a red light. i hope this will fix your problem
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