Having to reprogram car after it sits.

[gsloth]

I thought this problem was solved, but it just happened again the other day. Shortly after my fuel system upgrade (gt40 pumps/fpdm), If my car would sit longer than 24 hours or so, It would start, but run terribly, backfiring/wanting to stall. Every time a reflash of my tune would fix it and it would be fine. If the car was drivin daily, it never had this problem. I called SCT, they were no help-> after being on hold for a while, they told me "have your tuner check the car for mechanical issues.", . thanks guys. Long story short, my tuner turned off adaptive learning and I have since not had issues, even if the car sat for over a week, it has been fine. A couple days ago though it had sat for several days and started with the same crappy running/backfiring I used to be accustomed to, and a simple reflash fixed it again.
Anyone else experience anything like this? The adaptive learning definitely fixed it I thought, as it went without issue for a few months, but now I have no idea what would be causing this, its like the ecu is going into dummy mode for some reason if the car sits for long periods.

Using the SCT xcal2 by the way.

 

[T-Pain808]

Sounds like the Ecu has no memory for some reason. If you get another ecu
though it gonna cost some dough. If possible I would try someone else SCT first, which I doubt will work, then try another ECU. Ya, I know thats a tough one.

 

[prostkr]

Before trying to reflash next time, make sure the battery is fully charged. Having a low or weak battery will cause problems with the pcm flash.

 

[gsloth]

Before trying to reflash next time, make sure the battery is fully charged. Having a low or weak battery will cause problems with the pcm flash.

I had it checked months back for electrical issues, and everything tested out fine, including the battery. It's like the tune only sticks for so long, then it "loses" it if the car isn't run for x amount of time.
I'll note here that I haven't experienced this again since it happened last time, but I figure its about time to get down to the bottom of this, and buying a new ecu would not be the most ideal situation.

 

[sweet88gt]

I would talk to someone else about the tune. Adaptive learning (if Im right) is a good thing to have. Everytime you start the car and drive the computer is learning a new strategy for keeping all parameters in check. Adaptive learning keeps A/F and multiple other items in check for the best MPG and so on. Check this tuners website out and shoot him an email with whats happening. His name is Justin and is very helpful
http://www.vmptuning.com/store/index.php?
He tuned my car and is only into SCT software. He should be able to help.

 

[rrpederson]

im no mechanic by any means, but maybe its an issue with the ecu itself. think of the clock in your car. if it always has power, it will always have the correct time, with the exception being if the clock itself is broken. but if u disconnect the battery the time goes with it. perhaps the ecu isnt getting constant power or something of that nature. so after a certain time, something changes, like a power save mode or something and it suts off something that is supposed to be on all the time.

 

[gsloth]

^ Well thats the thing, I just put on a new heat exchanger yesterday, which required unplugging the battery for about 4 hours, and then the car started right up and ran fine. As far as the tune and adaptive learning goes, it does make sense that its a good thing to have, but I have actually been getting 22mpg with it off.

 

[bigmoose]

does your oil smell like gas? i had my FRPS go bad. no code. Car ran like crap with misfires. if i reset the computer by unplugging the battery it would go away for a short while until it started relearning and would come back. was FRPS was bad and causing a high fuel pressure making me run super rich, hence the oil smelt like gas.

 

[gsloth]

does your oil smell like gas? i had my FRPS go bad. no code. Car ran like crap with misfires. if i reset the computer by unplugging the battery it would go away for a short while until it started relearning and would come back. was FRPS was bad and causing a high fuel pressure making me run super rich, hence the oil smelt like gas.

no gas smell

 

[HISSMAN]

The ECM will not lose a flashed tune, even if you leave the car parked for 20 years with no battery. You will lose adaptive, but that should not cause issues like you describe. I an on my iPhone right now, so I will try to read up and give you a better answer later.

 

[HISSMAN]

Also, do not drive your car with adaptive learning off. This is for tuning purposes only.

 

[gsloth]

The ECM will not lose a flashed tune, even if you leave the car parked for 20 years with no battery. You will lose adaptive, but that should not cause issues like you describe. I an on my iPhone right now, so I will try to read up and give you a better answer later.

Thanks, appreciate it. I have been beating on it for months with adaptive learning off with high boost and things have seemed to be doing really well :shrug:

 

[Justin@VMP]

It sounds like the computer was learning bad things and applying a correction that was causing it to run right, hence the need to reflash the PCM to reset adaptive, or to turn adaptive learning off. I would look into why this his happening, like bad O2 sensors or a vac leak.

The computer forgetting, loosing a tune, or having bad memory is virtually unheard of.