A bit of help if I could, pleases. I'm pretty new to the forum and Ford's as well for that matter.

I changed my 4 yr old battery in my truck today. It was running just fine prior to the change, but after the change, it would stall when slowing to a stop...just idle down to nothing. Started up just fine, but would keep stalling after slowing down. Very frustrating to slow down in neutral and keep the engine revved all the way home.

Any thoughts??? Could it be the onboard computer chip gone awry? Alternator gone bad? Any help is always greatly appreciated!

Thanks...Scott

 

It's probably nothing to worry about. Every time the battery is disconnected it takes a certain amount of time for the computer to relearn the idle. Try driving it as much as possible to speed it up. It could take as long as a week depending on how much you drive. This happened to me when my intake manifold gaskets were changed at the dealer and they disconnected the battery. My truck did not stall but came very close to it. After about 100 miles of driving it was back to normal.

 

Aren't there some vacuum lines between the battery and the fender well? Could one have been knocked loose when changing the battery? Would that cause the symptom? Could a wire have been knocked loose?

I would take the battery out and check for anything that got knocked loose.

Ummm... You did turn everything off when disconnecting and connecting the battery and you took off the negative cable first and installed it last, didn't you? If you didn't and you caused an short and there was an arc, you could have fried something. It's not always a given, so it's hard to say.

Good luck and let us know if we've been of any help or not.

BTW, it would help if you told us what year, engine, etc. your truck is.

 

When I did the pvc intake mod I disconnected my battery to re-set the computer and then followed the instructions in the owner's manual for "re-setting the emissions controls in case you failed an emission test".

For my '99 this involved starting the truck(obviously) and driving at least 10(?) minutes on the highway followed by at least 20(?) minutes in stop and go in town driving with at least 4 periods of idling. Then park the truck for at least 8(?) hours to cool off and then repeat the process

The truck did run a little funny during this. On the highway going down a hill it acted like it had a compression brake and the AC would not work for about the 1st 10 minutes.

So, you may be experiencing something similar to this. Try looking in your manual and see what the drill is for yours.

 

Thanks for your input...it's all helpful.

I later looked in the owners manual and followed the steps after disconnecting the battery. This seemed to help for a bit, until I drove it this morning...stalled just as I got to work. After work, I drove around more hoping that my chip wasn't a slow learner...no stalls but it did idle very low. This evening, it's idling around 700 rpm or just above. A couple more days and it should "graduate" from this relearning process.

I did go back and check to see if I had accidentally knocked something loose...fortunately not. Disconnecting the battery was neg. first...pos. last, etc. No arcs were seen during the disconnect. I haven't looked at the process to re-set the emision controls yet, but that sounds like the typical driving that I do anyway. A couple of days more and this problem should pass.

Thanks again. BTW...I have a 97 4WD 4.6liter Supercab. Only mod is the K&N airfilter so far.

 

I would like to chime in for all future people. 2012 F-150 5.0L. I replaced my steering rack and programmed myself. As per the huge F-150 maintenance manual that floats around this forum, it called to disconnect battery. I did so, and when everything was done the truck ran horrible. I mean everytime I came to a stop it would stall. It was like it was getting choked out of air. I bought some throttle body cleaner, removed the throttle body from the truck, and also the brass flapper from the throttle body to completely clean. Reinstalled the components and the truck ran like a dream. I would assume like everyone else has said, the truck air/fuel adjusted according to the throttle body getting more and more clogged. A simple clean and were running amazing.

Thanks everyone for all the input, saved my bacon!