ericdawe
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« on: March 03, 2016, 09:39:55 AM »
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Im having a bit of an issue.
2001 S4 6 speed. Mbox.
Was all stock. I was getting a lot of fuel smell on warm up, and while driving. It turned out the fuel injectors were coming apart, and I was getting fuel leaking between the plastic top and the metal body. Purchased a set of OE replacement injectors from Napa. Turns out the new injectors leaked worse then my OE ones. New plan time. I ordered a set of the Giant Green 42# injectors off ECS at the suggestion of a friend (planning for future upgrades). Install was straight foreword, made my own spacers. Now to tune for them.
Fired up NefMoto, downloaded my Rom, and made some changes. From reading on S4Tuning Wiki, it appeared that I only needed to adjust my KTKRE based on a 34.125 multiplier. I came up with the number .065625 for KRKTE considering the 520cc/min flow at the stock 4 bar. I then moved on to the TVUB (latency) table, and adjusted based on known values for the Giant Greens. If this were a Subaru, id be done, fire up the logger, go for a rip.
Everything seemed hunky dory. Flashed, started it, and let it idle. At idle fuel trims sit near 0, + or - 5%. Great. Grabbed my scanner and pulled out of the driveway. part throttle cruise shows same numbers at idle, great again. Once up to temp, I rolled into the throttle, and uh oh. Terrible misfires, wideband reads full rich, 7.5 afr, and fuel trims 0 out. I've checked, and rechecked my numbers and researched, and I cant figure out where I went wrong. Did I miss a table change for adjusting for larger injectors? what is the .000111 multiplier talked about on the S4wiki? It runs beautifully at idle and part throttle, and A/Frs are spot on, but Im not willing to get anywhere near WOT to get a log. What did I miss?
For background, Im only a newbie tuner on VAGs, if this were a Subaru, id have been done hours ago. I have very strong knowledge of how OL/CL works, and all the nuances of fuel control, knock control, and everything else to do with tuning. Ive tuned quite a few high power Subaru's and Nissan's. What am I missing with this Audi? I feel like a shaved tail louis.
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ericdawe
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« Reply #1 on: March 03, 2016, 10:50:29 AM »
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Doing some more reading. Ive decided to recalculate my base KRKTE number based on the adjustments for Heptane content. I found the equation somewhere here. It lowers my number into the .062XXX range. This should theoretically lower overall fuel delivery, hopefully this brings my A/Fr's into a happy place. It just doesn't seem like enough difference to adjust for a 7.5 A/F'r. I still feel like I'm missing something somewhere.
If it seems to make the A/Fr's more reasonable, Ill pull some logs, and post them up.
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nyet
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« Reply #2 on: March 03, 2016, 10:53:27 AM »
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i'd just do stock krkte * (old flow/new flow)
gg's flow about 520 at 4bar so thats stock krkte * (349/520)
tvub for gg's should not be much different from stock.
Anyway, check for intake leaks etc. as well.
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ericdawe
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« Reply #3 on: March 03, 2016, 10:58:56 AM »
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i'd just do stock krkte * (old flow/new flow)
gg's flow about 520 at 4bar so thats stock krkte * (349/520)
tvub for gg's should not be much different from stock.
Anyway, check for intake leaks etc. as well.
Stock KRKTE number resulted in massively rich at idle, part throttle, cruise, and from what I tempted of WOT. Fuel trims max out in the negative, and it sets rich codes. The Latency table wasn't massively changed. Just little adjustments across the voltage range. If I shouldn't use the KRKTE number to adjust for increase in flow, then what should I use? No intake leaks, tested with smoke machine. Spark plugs replaced to make sure they didn't get fouled after trying stock KRKTE. |
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« Last Edit: March 03, 2016, 11:02:05 AM by ericdawe »
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nyet
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« Reply #4 on: March 03, 2016, 11:01:01 AM »
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i didn't say use stock krkte, I said multiply it by (349/520)...
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ericdawe
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« Reply #5 on: March 03, 2016, 11:15:00 AM »
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i didn't say use stock krkte, I said multiply it by (349/520)...
Gah, I didnt interpret your * as a multiplication symbol. Im riding the struggle bus today. Using that equation I land on a number of .0653XXX, which is only 3 10,000ths off from my original number. I also have the heptane adjusted number which is in the .062s. What I really want to know, is if there are, strictly speaking, any other tables that NEED to be adjusted to compensate for the larger injectors? |
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nyet
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« Reply #6 on: March 03, 2016, 11:22:50 AM »
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Nope. Something else is amiss. EGT?
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ericdawe
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« Reply #7 on: March 03, 2016, 11:29:36 AM »
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Nope. Something else is amiss. EGT?
So no magic wand then? My EGT sensors have been dead since I acquired the car. They're disabled in the tune. The car ran well enough before changing injectors. I've also set up a Stage 1 map for the car, so Im tempted to load that. I wonder if I corrupted something somehow. Maybe its time to go back to square one. Anyone have a virgin 551M bin file? Thanks for all your help by the way. I fell like I smashing my head against the wall. |
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contrast
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« Reply #8 on: March 03, 2016, 12:52:32 PM »
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Check your PM
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nyet
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« Reply #9 on: March 03, 2016, 04:49:03 PM »
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