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Boost Creep
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Discussion Starter #1 (Edited)
Hey guys,

I have a bit of a scenario every time my battery goes dead wondered if this happens to you? I assume its ECU or VPC related?

So i go to drive my car last night and turn the key over, click, nothing. OK, battery is probably dead? I go to local auto store and pick up a battery charger and let it trickle charge all night.

Get in this morning, turn it over, turns right on... but is running like shit again. So I go to take it for a drive, and its stalling on the road when you come to a full stop, rpms drop to nothing and it stalls etc. OK I remember back before this was happenening whenever the battery went dead, it was like the ECU needed to relearn and you had to drive around for awhile and the car would be ok.. So i drove around for about 45 minutes and the car seemed to be running better. I then attempted to go WOT a few times and was seeing 13.1 and I know thats not good. I also was getting a smell, that didn't smell to good.

So I continued driving around and then went WOT again about 10 minutes later and it was seeing 12.3 at WOT. I know thats still lean, will this correct itself? Do I need to reset the ecu? Ever see this happen? I know thats not terribly lean, but I was just curious.

It seems the issue is only at low RPMs. I'm running AFC NEO and VPC and EVC6. Fuel pressure reads fine, boost is fine.

Is anyone else having issues like this when they lose connection to the battery, or the battery dies?

FYI the gains on the vpc were all set to 12oclock. They are never touched.
 

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Newbie
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My car runs like crap every time the battery dies. It won't even idle by itself, I need to give it gas as soon as I start it. When driving for the first time, I actually have to brake with my left foot and give it gas with my right foot simultaneously to keep it from stalling at stops. Like you said, the ECU needs to relearn the fuel curve.
 

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Battery dies on me yesterday after not driviing for over a week due to non stop rain.Hopefully this wont happen but yeah the more you drive the car the faster the ecu will relearn everything.
 

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Boost Creep
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Discussion Starter #4
It seems to be fine now after 45minutes of driving. I guess that is one of the drawbacks when not running a standalone.

I was curious if this was specific to me, or it happened to everyone. It seems to be hit or miss.
 

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When I had the VPC/AFC I had zero problems. I even had 800cc++ injectors, dual densos etc and had zero problems.

I tuned it myself and made sure that all my longterm fuel trims were in check and never had a problem. Sounds to me like people are relying on their ecu to used the closed loop feedback correction to make fueling adjustments. The ecu can only adjust so much. You need to tune your car so that the adjustments that the oem ecu makes are very small. Other wise you are going to have to wait until it can relearn over time.
 

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?!!?HABBA BABBA??!!
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my battery craps out on my car too if I just leave it sitting for a while.
 

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I spoke too soon.I drove her today finally after 7 days of rain and she running alittle rough.Im gonna drive around for awhile after work to see if it helps with the process. :(
 

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Boost Creep
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Discussion Starter #8
I spoke too soon.I drove her today finally after 7 days of rain and she running alittle rough.Im gonna drive around for awhile after work to see if it helps with the process. :(
Drive for 45 minutes or so, let me know how its running after that. My car runs TERRIBLE once the battery has been reset, it usually corrects itself.
 

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Drive for 45 minutes or so, let me know how its running after that. My car runs TERRIBLE once the battery has been reset, it usually corrects itself.
I drove for around 30 mins after work on the bush (local tollway) and at first car was leaning out into the low tens at idle but by the time i got home it had pretty much corrected itself .I didnt drive her today but will for sure tommorow to see if anything has changed but it seems to be back to normal now.
 

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Boost Creep
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Discussion Starter #11
I drove for around 30 mins after work on the bush (local tollway) and at first car was leaning out into the low tens at idle but by the time i got home it had pretty much corrected itself .I didnt drive her today but will for sure tommorow to see if anything has changed but it seems to be back to normal now.
Low 10s would be rich...

14.8 would be around where you wanted to be at idle.
 

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Boost Creep
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Discussion Starter #15
If my battery go dead and I jump her she runs fine no stalling or stuff and I have a vpc/gcc in my Lexus.
I think I might have some custom ECU work or something, I dont know. It seems hit or miss with some folks.
 

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Im still actually kinda rich at idel well actually everytime i come to a light and put it into neutral.Im getting 10.8-11.4 on my wb.Should pull the ecu fuse to reset everything or what??
 

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Boost Creep
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Discussion Starter #18
mkiv, your untuned bro?


Your in TX, get your butt down to mvp or bl..
 
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