Disconnect battery cable - Now rough Idle

[Joe DeVola]

2004 Explorer XLT

I disconnected the battery cable for a few hours while working inside my wife's Explore and now the car has rough idle. Did the computer get discombobulated? Can I restore whatever I did wrong?

 

[ponkotsu]

2004 Explorer XLT

I disconnected the battery cable for a few hours while working inside my wife's Explore and now the car has rough idle. Did the computer get discombobulated? Can I restore whatever I did wrong?

Give it a couple days and allow to relearn the engine.

 

[Number4]

Assume you have the 4.6?
Remove the air intake hose from the throttle body, flip up the valve and wipe the area with a clean dry rag.

 

[turborich]

Assume you have the 4.6?
Remove the air intake hose from the throttle body, flip up the valve and wipe the area with a clean dry rag.

Really? This is the worse advice I have heard.

Drive it for a few days as stated and it "should" relearn your driving habits and should go back to where it was. Keep us posted.

 

[Number4]

Nice comment turdorich. One, it's rude and not helpful two it's ignorant.
I wouldn't have mentioned it if it didn't work. I'm in this forum because I own an Explorer with the 4.6l. It's called experience with results.

Why do you think it's having to "re-learn" something? Should it have to? Perhaps there is an issue throwing it out of spec. Do you know what that issue is? Perhaps it's oil passing through the pcv system and collecting at the valve on the throttle body. Perhaps over time this causes a buildup, even if slight, that the vehicle has to compensate for. Perhaps removing this sludge allows the vehicle to function properly.
Oh no, let's ignore the obvious issue and wait until the car re learns to overcome the issue. Yes. That's the best plan.

Here's another perhaps for you. Perhaps you've read the TSB from Ford that recognizes this issue with as little as 10k miles on the engine!!!!

 

[SaltKing]

The obvious answer is related to disconnecting the battery, if it wasn't idling rough prior to disconnecting it.

There is a proper procedure for allowing the computer to "re-learn" trim settings and such; start the truck, let it idle until it reaches operating temperature, turn on the A/C and run for a minute, turn off the A/C, allow the truck to continue idling for another minute or so, then drive it for awhile (20-30 miles) on city streets and highway (if possible). This is what I remember, you might search the forum to find a better description of the procedure.

It could, of course, be a separate issue but this is the most obvious place to start with the information given.

 

[BigRondo]

Here is the "Relearn" procedure from my owner's manual. If you don't have an owner's manual, it can be downloaded by clicking here:

Here is a great video by makuloco2000 for Resetting the PCM after repairs are made or the battery has been disconnected:

http://www.explorerforum.com/forums/showthread.php?t=396533

Good luck getting it sorted!!

 

[Number4]

Here is the "Relearn" procedure from my owner's manual. If you don't have an owner's manual, it can be downloaded by clicking here:

Here is a great video by makuloco2000 for Resetting the PCM after repairs are made or the battery has been disconnected:

http://www.explorerforum.com/forums/showthread.php?t=396533

Good luck getting it sorted!!

I like the last step they felt like mentioning in your pic. Just in case people didn't realize that the clock was now wrong. Too funny.

 

[Number4]

Really? This is the worse advice I have heard.

Drive it for a few days as stated and it "should" relearn your driving habits and should go back to where it was. Keep us posted.

FYI- 2nd page, second post, you'll see my recommendation. Second page, last post by OP, you'll see what the OP paid the dealer to do that he could have done for free based on my post.

http://www.explorerforum.com/forums/showthread.php?t=391403&page=2

 

[Joe DeVola]

I'm the OP and here's what I did. I called a mechanic that has worked on my car before. He told me to disconnect both battery cables and touch them together. Did that.

I also just had my transmission rebuilt on my Dodge Ram and since I had just handed over $1700 to him I thought I'd ask him if he had experienced the same problem on vehicles that came into to his shop after competing work on them. His head general mechanic gave the instructions given to me, above, from an Owner's Manual. In addition, he said the clean the throttle body.

After doing what my local mechanic suggested, that is the battery cable touching trick and cleaning the throttle body (a 10 minute shade tree mechanic's cleaning), everything works fine.

I'm sure the cleaning the throttle body is always a good idea but the idling wasn't a problem at all until I disconnected the negative battery cable last weekend to work inside the car.

I'm happy and thanks to all who took the time to help me.

 

[turborich]

Nice comment turdorich. One, it's rude and not helpful two it's ignorant.
I wouldn't have mentioned it if it didn't work. I'm in this forum because I own an Explorer with the 4.6l. It's called experience with results.

Why do you think it's having to "re-learn" something? Should it have to? Perhaps there is an issue throwing it out of spec. Do you know what that issue is? Perhaps it's oil passing through the pcv system and collecting at the valve on the throttle body. Perhaps over time this causes a buildup, even if slight, that the vehicle has to compensate for. Perhaps removing this sludge allows the vehicle to function properly.
Oh no, let's ignore the obvious issue and wait until the car re learns to overcome the issue. Yes. That's the best plan.

Here's another perhaps for you. Perhaps you've read the TSB from Ford that recognizes this issue with as little as 10k miles on the engine!!!!

What you stated has nothing to do with the issue at hand. You just threw it out there. The OP didn't say that this issue happen after driving for several thousand miles or anything like this. The battery was disconnect and that's when the issue started. How is wiping / cleaning the throttle body going to have anything to do with this? It's not. :thumbdwn:

 

[Number4]

Turbo, are you dense? The sludge passing through the PCV valve builds up on the throttle body air valve. This happens over time and the Ex learns to compensate for this added resistance when adjusting the air flow. When you pull the battery cable it loses this memory. When powered again it acts as if it's 'new,' except it has this resistance to deal with that it is no longer calibrated to handle.


Just to be clear, this issue starts, after, the battery cable has been disconnected, because that's when the ECM loses it's learned settings. Baaattterrry cable disconnected......

 

[extsp2]

You are all correct. Number4, if you had mentioned that reasoning in your first post I'm sure you would not have had to explain yourself later. We're all here to help each other but sometimes you need to back up what you're telling someone to do so it makes sense to people that might not have as much experience as yourself.

 

[Number4]

You are all correct. Number4, if you had mentioned that reasoning in your first post I'm sure you would not have had to explain yourself later. We're all here to help each other but sometimes you need to back up what you're telling someone to do so it makes sense to people that might not have as much experience as yourself.

Very true, my error in not originally explaining the why. Im not accustomed to having too and this does pose an issue when working with people that don't know you.

 

[BigRondo]

I have been watching this thread for a while. I would like to ask everyone to play nice! :biggthump

 

[shucker1]

Ditto...

Copy that!