Did a complete walk through of best practices to give you guys a look before you flash your own cars. Makes it much easier knowing what’s coming before it arrives!
Thanks man, this is of great help!
Can you explain a bit more about the post-procedure steps i.e. start driving the car before the cold start cycle completes? How many times do I have to do this?
My normal habit is to start the car, wait for cold start cycle to complete and the idle RPM to come down before i start driving.
Audi actually states to do this ALL the time. Page 70 of your manual. When you flash, you end up erasing all the short and long term fuel trims. By sitting there and letting it get down to normal idle or even longer, you’re essentially dialing in the wrong fuel trim and it can get wonky with time. Just start driving within three to five seconds after starting the car.
The fast idle will actually continue but it will change a bit in tone before settling into a steady idle. I’ve been practicing what I’m preaching for the past week and it made a difference.
Noted. so start car, start driving before fast idle (cold start cycle) ends basically.
what are the differences you have been noticing then? better mpg? or better power?
Better cold idle and throttle response from cold until warm. If you continue to let the car warm from cold start without driving, the throttle becomes snatchy until the car starts to warm up. Doesn’t affect anything else.
Good to know. Probably why my entire house smelt like gas after the new flash LOL
Neat video ape_
Just to add to the cold start. On all of the V10 motors. It says very clearly in the owners manual DO NOT LET YOUR CAR SIT AND IDLE ON A COLD START… It even says this is bad for the motor.
On cold start. Your motor reads off NONE of the sensors while in the cold start sequence. So it defaults to the base injector pulse and LTFT data. So if your car warn starts good but cold starts rough you need to look into getting your fuel adaption sorted and all of your readiness monitors to run.
What exactly is cold start. What exactly is going on in cold start. Why do you NOT want to sit and let the car idle in one spot to warm up… Before I start… this is 100% how every combustion motor from every motor company is programed from the factory.
When the motor is cold and the outside temps are below 65f in most cases. Cold start warm up is triggered. Cold start is always triggered when the motor has not ran after a set amount of time. But cold start warm up is the most aggressive.
KEEP IN MIND THIS IS ALL 100% from the FACTORY TUNE —
During cold start warm up. Your 02 sensors / MAF (if you have one) / Coolant temp sensor and other motor sensors are not sending feedback for a set amount of time. As they themselves are not up to operational temp. Your 02 sensors control your cars AFR ratio and due almost all of the work. They themselves need to warm up and you might have seen codes for your 02 sensor having a faulty heating element.
KEEP IN MIND THIS IS ALL 100% FROM THE FACTORY TUNE —
With none of the sensors that help your cars idle and combustion stability sending feedback your ECU is sending a pre determined amount of fuel with the sole intention of running the car rich. As lots of extra fuel help warm up the motor faster. This is also for helping to warm up the cats but that is another issue for another post. The colder the ambient temps are the more fuel the ECU will deliver to help and try to warm up the motor.
When I say the motor runs rich I mean richer fuel to air mixture than you might see when you’re under WOT throttle conditions. So to warm up the motor during cold start warm up… the fuel to air mixtures are richer than you would see in a WOT condition. Think about that for a second. Then to make it worse (or better for quick block heating of the motor) your ECU is pulling back ignition to leave combustion instability to help speed up the warming even further.
This is why you can see some cars with no cats that have the OEM tune have black soot on the bumper and inside the tail pipes. This is why people get the JHM tune to help but that is another point to make.
No matter what your motor needs to go through cold start. While cold start warm up is more aggressive with the fuel then just a simple cold start. Cold start cycle is still running much richer than when the car is warmed up.
WHY NOW AFTER A ECU FLASH OR A ECU RESET IS MY COLD START BAD —
Why is my cold start or cold start warm up now acting up Vs before you flashed or reset the ECU. Once you flash the ECU or fully reset the ECU. You reset the fuel trims and the LTFT data. This is one of the only offsets used during cold start. So if your cars fuel trims were normally rich and the ECU pulls fuel to keep the car in check. That has now been removed and the ECU is running even more rich. Add that to the adaption sequences haven’t learned. This is a loop that isn’t going to be fixed or improve until the adaptions are all set and the trims are worked out correctly.
OK I GET ALL THAT BUT WHY DO I NOT WANT MY CAR TO COLD IDLE IN MY GARAGE ----
When the motor is cold all of the components in the motor are cold. Most importantly your piston rings. The only thing stopping fuel from getting past your piston into your oil is your piston rings. As you give the motor more and more power under WOT acceleration your piston rings start to warm up and then close the ring end gaps more and more. This helps make more power due to more compression but it also keeps the extra fuel injected due to the extra power out of the oil.
Obviously you don’t want fuel in your oil. Oil contamination by fuel causes the oil to break down and we all know how important good oil is. One of the reasons your oil temps are allowed by the factory to get so hot is to help burn off all of the fuel in the oil caused in part by cold start fuel contamination.
What’s the long story short part of all this? When do you see the harshest conditions in the motor. — cold start ---- When do you see the most fuel contamination into the oil — warm up cold start. What is one of the worst things you can do to warm up the car during cold start or warm up while there is tons of extra fuel being used… Let the car sit at idle.
What is recommended by the factory and most others for long term health of the motor. — Start the car let the car start and give about 3 to 5 seconds to bring the oil pressure up. Then drive in low load at lower rpm speeds as quickly as possible.
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wow thanks for the read. I have been doing it wrong for maybe 1/3 of the time -_-"k
glad i am doing the flash in a month’s time, that ought to reset all my fuel trims then. will that fix my issue?
Should…you’ll be starting over from scratch so just make sure to do it right and you should be good!
Very interesting read here guys think most of us have been doing it wrong for a long time 
Great bit of info there @justincredible thank you dude 
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Cold idle is harder on a DI motor than a Port injected motor. When cold they all cycle to a rich mixture for the cold start and that mixture directly injected washes the lubricants off of the cylinder walls much more so than on a Port injected motor. So they say start it up, get the seatbelt on (give oil pressure a chance to reach the valvetrain), then drive off and drive easy until oil temps are up to normal. Driving easly also causes the engine to warm up quicker than idling which gets you off of the Rich mixture cold start cycle.
And if you’re not doing it already, make sure your center display lists oil temperature. You can cycle through the displays using the button on the bottom of the right stalk, same one that shuts down that annoying car door open buzzer. I do not go above 3,000 rpm until temps reach 145F. I generally don’t go above 6,000 rpm until temps are in the 190 range. A little paranoid, maybe, but I like everything good and warm before hitting an 8500rpm redline.
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Hello guys, Just wondering if I will be charged full price or anything at all if i go to a new revision of stage 2 once i get the headers and LWFW in a few weeks. since i now have the cable and wanna flash to see a before and after and make sure my car works well and everything. Ive tried contacting JHM through their phone number and email but no response yet.
If you log in, see if you have any flashes left. You’ll need two, one for ECU and one for TCU. But just reach out to me and we can see what flashes are available and I can walk you through it.
If you contact them through email, it’s good to include your login information so it helps them (quickly) find you and assess your flashing situation.
Forgot to ask…which shop did you end going with for the work?
Yeah on my account through their website it says unlimited remaining downloads and thats about it. Im not on their server yet since i dont have my log in info which is what they provide correct?
I ended up going with a mechanic i found a while back that is really good with any european or any cars and vehicles in general, he is currently building a new 911 turbo and has everything taken out in his shop so no space for me so just waiting on that.
Forgot to mention that i only have apple devices and i am planning on getting a friends help a few minutes away with both a windows computer and battery tender, just waiting for a response by JHM to leave so i dont waste anyones time
Did you purchase stage 2 already? Can’t remember…one of those days!
Yes, and filled out and submitted the form for the tuning sign up
And you purchased it through me or directly through JHM?