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s5fourdoor
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« on: August 13, 2012, 09:21:24 PM »
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Hi Guys - I was just wondering about a few things. There are a few problems on my m-box tune, which has been mostly RS4-ified by me.
The issues seem to be consistently the same thing and are only occurring under a fairly repeatable set of circumstances.
These problems are in order, and I wish to address them independently:
1) on pure cold start the car semi-starts, stumbles and shuts off, runs perfectly on second full ignition sequence every time.
does this mean i'm running lean or rich, too much or too little timing? which maps do i need to repair for this?
2) on full-temp start, i get the same exact thing every time when i repeat a certain thing. i start from my house which is on top of a hill, as i descend this hill very slowly, i often get misfires. often times the car goes super rich when i'm braking slowly down the steep hill. i know the car misfires sure, but i feel like its relating to the actual hill. is it possible i'm getting fuel dumping from some evap system? the car misfires a good bit, which i thought was from lean conditions. any thoughts? often times this occurs at the same time as the brakes feeling a bit strange. i checked and replaced the brake booster hoses and all brake components including calipers, rotors, lines, and pads are brand new. could this mean therefore that i need a new master cylinder or brake booster? i'm clearly all confused on this particular issue, but it really only occurs on hot-starts down this slow hill and causes every cylinder to mis-fire. does anyone know the variables i'd need to log the relevant variables for this?
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« Last Edit: August 13, 2012, 09:24:02 PM by nehalem »
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nyet
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« Reply #1 on: August 13, 2012, 10:18:44 PM »
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Maybe fuel pump check valve, or just really cold plugs?
The brake thing might be the brake booster check valve..
finally, regarding AFR: generally AFR related misfires are from being too rich, not too lean.
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s5fourdoor
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« Reply #2 on: August 13, 2012, 11:26:11 PM »
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Maybe fuel pump check valve, or just really cold plugs?
The brake thing might be the brake booster check valve..
finally, regarding AFR: generally AFR related misfires are from being too rich, not too lean.
Ahh great stuff. OK I know for a fact all of the brake booster stuff including the check valve is ok and new. I also know i installed a fuel pump check valve on top of a b5 rs4 pump, so that's also ok. What plugs and gap do you recommend? I think I'm due for a swap of these anyways... |
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jibberjive
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« Reply #3 on: August 15, 2012, 12:59:58 AM »
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What turbos are you running again?
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s5fourdoor
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« Reply #4 on: August 15, 2012, 08:13:20 AM »
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K04
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jibberjive
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« Reply #5 on: August 16, 2012, 11:58:43 AM »
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Most people just run BKR7E's gapped to about .28 with K04's and stock coils.
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silentbob
Full Member
Karma: +30/-1
 Offline
Posts: 141
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« Reply #6 on: August 16, 2012, 01:16:16 PM »
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Hi Guys - I was just wondering about a few things. There are a few problems on my m-box tune, which has been mostly RS4-ified by me.
The issues seem to be consistently the same thing and are only occurring under a fairly repeatable set of circumstances.
These problems are in order, and I wish to address them independently:
1) on pure cold start the car semi-starts, stumbles and shuts off, runs perfectly on second full ignition sequence every time.
does this mean i'm running lean or rich, too much or too little timing? which maps do i need to repair for this?
Sounds like too lean. To be sure what the problem is you have to log lambda with a external wideband, nmot, zwout, zwstt, miistt, wdkba, rl, fst and ps during cold start. 2) on full-temp start, i get the same exact thing every time when i repeat a certain thing. i start from my house which is on top of a hill, as i descend this hill very slowly, i often get misfires. often times the car goes super rich when i'm braking slowly down the steep hill. i know the car misfires sure, but i feel like its relating to the actual hill. is it possible i'm getting fuel dumping from some evap system? the car misfires a good bit, which i thought was from lean conditions. any thoughts? often times this occurs at the same time as the brakes feeling a bit strange. i checked and replaced the brake booster hoses and all brake components including calipers, rotors, lines, and pads are brand new. could this mean therefore that i need a new master cylinder or brake booster? i'm clearly all confused on this particular issue, but it really only occurs on hot-starts down this slow hill and causes every cylinder to mis-fire. does anyone know the variables i'd need to log the relevant variables for this?
At what elevation do you live? TATEIST_W is the control pwm of the evaporation system valve. |
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s5fourdoor
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« Reply #7 on: August 16, 2012, 02:00:08 PM »
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silentbob, omfg thank you so much. let me go back and try to process what all of these keywords are and where they are located in the me7 logger.
the problem has been temporarily solved by setting kfpbrk/kfpbrknw/kflf to 1.00. additionally, i set vbat (tvub) slopes to match the flawed bosch-dealer injector spec-sheet and scaled them so they hinged on .80ms @ 14V. my plan is to keep this constant and adjust fkkvs moving forward.
first however, i'm going to try using this new start-file to retarget my krkte using the combo me7 logger / innovative wb-o2 utility.
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airtite
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« Reply #8 on: August 20, 2012, 08:42:29 AM »
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I have a similar issue with my brakes specially on cold start, I have done quite a few vacuum line deletes etc and what it looks like to me is that something to do with my load at idle on cold start causes the system to not have enough vacuum and therefore the brakes feel really hard. With a stock kfmirl it doesnt seem to do it.
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s5fourdoor
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« Reply #9 on: August 20, 2012, 10:39:18 AM »
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I believe the issue is occuring only when I'm warm-starting. Rick had mentioned in a post I read that his EV14's only had warm-starting issues.
What I can't figure out is if misfires come from too much or too little fuel. It seems like both can cause them because the STFT attempts to adapt. The STFT adapting of course eventually gets the target, but first there's a shit-load of fueling variance.
I read a post somewhere that said the following. If you experience a cold-start problem, don't bother with the cold-start remapping. You goto the {7,10,12} volt sections of TVUB and target a change of .10ms. Then apply this .10ms as a percentage to the {7,10,12} volt using the current 10V value as the base value. For instance: Current 10V: 1.52. 1.52-.10 = 1.42. ln(1.42/1.52) = -0.068 ~= -7%
Then apply this -7% or new_val= .93 * old_val to the {7,10,12} volt values. Apparently if you repeat this every-time you have a difficult cold-start, you will eventually find the correct target and your problem will be solved. This technique seems logical to me because all of my cold starts seem to be the engine choking, like there is too much fuel or something. idk exactly, but be aware that during a start, the starter load will bring the system down to 9.5-10.5 volts, hence targeting this {7,10,12} set.
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« Last Edit: August 20, 2012, 10:40:51 AM by nehalem »
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marcellus
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« Reply #10 on: August 21, 2012, 11:59:10 AM »
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silentbob, omfg thank you so much. let me go back and try to process what all of these keywords are and where they are located in the me7 logger.
the problem has been temporarily solved by setting kfpbrk/kfpbrknw/kflf to 1.00. additionally, i set vbat (tvub) slopes to match the flawed bosch-dealer injector spec-sheet and scaled them so they hinged on .80ms @ 14V. my plan is to keep this constant and adjust fkkvs moving forward.
first however, i'm going to try using this new start-file to retarget my krkte using the combo me7 logger / innovative wb-o2 utility.
Interesting, can you explain the reasoning why you set the KFLF to 1.0? From what I have seen that map is ususally left stock. I have to look up he other two to see what they do. |
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s5fourdoor
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« Reply #11 on: August 21, 2012, 12:49:09 PM »
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Interesting, can you explain the reasoning why you set the KFLF to 1.0? From what I have seen that map is ususally left stock. I have to look up he other two to see what they do.
I'll leave an exact definition to somebody a bit more knowledgeable than me. What I do know is that the RS4 ecu has this set to all 1.0244... that's my rationale here - it appears Audi didn't really use this map for the rs4, so its one easy source of variance to eliminate. |
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marcellus
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« Reply #12 on: August 21, 2012, 02:57:29 PM »
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Well, that kinda sucks. I have been looking at this map sideways since I started down this path. There was never no real reasoning as to why it was populated the way it was. I like the idea of setting it flat.
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