Changing battery caused problems

[jsealey]

Just when I think I have one problem fixed something else goes wrong.
Yesterday I changed my battery as the old one was weak. It was still starting but turning over real slow and the voltage would drop so low it would make my two way radio shut off. Anyway before the battery change I was having drivability problems that pointed towards MAF sensor being the problem. Found air breather warped and letting unfiltered air in. There was a piece of crap on the MAF I blew it out and fixed the air breather and all seemed well. Then I changed the battery and the surging problem came back as well as high idle speed and the tranny started to shift wierd. When slowing down it downshifts and the rpms will jump like its a forced downshift. The idle will drop to 1500 then slowly come down to 1000. It used to idle at 800. I just disconnected the battery and let it sit for a while to reset the computer. Will see what happens. Anybody else have this type of problem?

 

[BobWiersema]

How many miles have you put on it since you disconnected the battery?


Edit:
I'll look in my 2000 service manual. I think you can by pass the cold soak and get the computer back on track quickly.

 

[BobWiersema]

I don't know if this is any help at all. You may just need to drive it a while to see if any codes show up. Anyway this is what was in the Ford book.

 

[jsealey]

Thanks for the feedback I don't think my $40 code reader is going to do anything like that. Like you said i may just need to drive it more. I have only driven 30 miles since changing the battery. Then I disconnected the battery and left the lights on for half an hour today. So I'm back to zero again. How long does it take for the computer to learn all the parameters to run properly?
Could my old battery be the cause of my previous drivability problems? If the voltage went low enough every time I started it on a very cold day(we have had a lot lately) would that reset the computer?

 

[BobWiersema]

Thanks for the feedback I don't think my $40 code reader is going to do anything like that. Like you said i may just need to drive it more. I have only driven 30 miles since changing the battery. Then I disconnected the battery and left the lights on for half an hour today. So I'm back to zero again. How long does it take for the computer to learn all the parameters to run properly?
Could my old battery be the cause of my previous drivability problems? If the voltage went low enough every time I started it on a very cold day(we have had a lot lately) would that reset the computer?

30 is not enough for the computer to learn. I have cleared codes without repairing the problem and they don't reappear sometimes for 150 to 200 miles.

As for the old battery problem, yes if it had a bad cell or two that was drawing the voltage down, that would cause problems while your driving.
Most engine sensors are variable voltage devices that require a good 12v source. So I guess time will tell, go for a ride but not to far from home.