HELP: Runs like crap once Battery gets Reconnected

So I've had this happen to me twice now, the first time I thought it was just a coincidence. I wired up my Hella 500 HIDs, and in doing so, I disconnected my battery. Everything with the install went very well, but when I hooked the battery back up, my truck ran like the timing was retarded or a vacuum line wasn't hooked up (coughing, sputtering, couldn't increase RPMs without it wanting to almost die). So I went thru all the basics (checked hoses, checked fuses) and it all looked good. Then I decided to clean my MAF sensor, and that seemed to help. I could now drive the truck, but it seemed to have loss of power (I wan't able to accelerate as fast). Eventually, the truck got back to normal and I just assumed the truck re-mapped it's fuel/air or something...? Anyway... I just installed some audio components to the rig this past weekend, and when I hooked the battery back up (wouldn't ya know it) the truck ran like crap again! SOOO, I checked my fuses and hoses/lines again, and ended up cleaning my MAF sensor again to get the truck drivable! Is this just coincidental??? Or is my truck going into some mode of relearning air/fuel or something???
Any feedback would be greatly appreciated, as I am at a loss of what to check/do next. Thanks!
- Matt

 

Wow... no replies after 85+ views..? This must be a rare issue. Looks like I'm SOL.

Anyway, thought I'd update the situation here. So each day since the incident, the truck has gradually ran better and better. The day after, I did a MIL scan and had a "Fuel too lean" code (which is always on anyway), and a pending code of "Engine Misfire." I cleared the codes and scanned again the next day, to only find the normal lean fuel code. I feel as tho it hasn't reached its full potential yet, and I really hope that it does! But this seems to me to be a prolonged re-learn for my truck... Any thoughts? What do you guys think???

 

Being that it got better after driving for awhile both times, that's more than likely your answer.

 

After each time I reconnect my battery, I have to cycle the key on and let the pump prime up, switch back off then start the truck. If I don't, then it does sputter and die. Try just cycling the key.

 

The Ecu's in these truck are self learning. You've gotta drive a handful of miles and it will get better with time.

 

Right on, that's what I'm hoping for! Thanks for the feedback!

Thank you so much for that info! I was not aware of that at all! I will def try that next go around! Thanks!

I've driven about 40 miles since... shouldn't it be "re-learned" by now?? Or do I need to put some more on it?

 

I have the tow package on my 06 dbl cab SR5 which comes with the 130 amp alternator, and a 27 battery ( upgraded to 29 ) you may want to check the voltage.. I can run anything ( so far w/o dimming problems.. looking to upgrade the amp with new kickers.. I have never seen my lights dim, but there is a 30amp fuse ( engine bay ) that may blow if grounds are faulted.. just for the record, I have led's on my boat trailer as well.

 

Mine is 03, but works the same, usually mine will start to run normal after about 5 minutes or so. I usually just start it and let it run on its own till the RPM's start to climb to normal idle and it smoothes out. By the way you always want to disconnect the ground first that way there is no chance of frying anything else.

 

It sounds as if you have a larger, underlying problem.

While yes, your truck will "re-learn" the proper mapping to achieve proper running conditions, the CEL should tell you something.

If your truck is attempting to learn some very LARGE changes compared to stock, it will take correspondingly longer.

Are there any other mods on your truck that would change it drastically?

When was the last time the O2 sensors were changed? They can become sluggish but still not trigger a CEL.

Furthermore, how does it behave normally? Are there any hot start issues.. any quirks... splutters... noises or otherwise abnormal running conditions that you've experienced?

 

Usually around 75 miles to reset

 

Shouldn't run that bad after just resetting the ecu.. Sounds like you got a lean problem, like he said start with the o2's

 

Thanks for the feedback!

I haven't replaced the O2 sensors yet, and not sure when/if they were replaced. I bought the truck w/ 87K on it, and now she has 130K.

Other MODs include K&N air filter w/ Downey intake, Airaid throttle body spacer, Flowmaster exhaust... I think that should be all that could possibly effect the learn time.

The truck normally has no issues and runs like a champ... until I have to unplug my battery for somethin.

Okay, thanks! I just got back from a 200+ trip from this last weekend, and my truck seems to be back to norm (great accel, runs smooth, idles smooth)! So I'm guessing that my re-learn time is considerably longer than if it were stock. Thanks for your help!

I've been told that replacing the O2's might not even stop the lean code just due to the fact that all my mods may have it thinking that it needs race fuel or something crazy like that! I use premium gasoline always, and the truck seems to run perfect, but will always throw a lean code (even after 10 mins of clearing code). So how important is it in MY situation to replace O2s?
Thanks for the feedback BTW!

 

Just updating the thread.
My truck continues to run great and back to normal now! I'll definitely have to try cycling the key next time I disconnect my battery and see if that makes the problem not happen. I'll keep ya'll informed. Thanks!