[Akurat]

Hello everyone!

Recently bought rav4 1998 4wd 4door with 117k km, full service history, which was working really well, but after changing the battery it lost the power and has a rough idle. Now I have to drive quite in a racing mode to reach normal not stalling conditions. Am I right that I need to relearn my old Rav? I read many forums, searched in manuals, find out some relearn pdf., but did not work for me. It seemed like when I drove it on high rpm for while it learned it and started to work close to properly, but after turning the engine off and starting again same shit happens. Someone had some issues like this before?
Thank you in advance!

Here in a maintenance part of service manual is saying:
When battery is disconnected, vehicles equipped with computers may
lose memory data. When battery power is restored, driveability problems
may exist on some vehicles. These vehicles may require a relearn
procedure. See COMPUTER RELEARN PROCEDURES article in GENERAL
INFORMATION section.

I saw videos in youtube for automatic transmissions, but I have a manual and did not find anything about that.
Maybe there is some special method for such a car. (My car has that old school diagnostics port, not obd2) Did not find much information about it either.

 

[Mick Hatzo]

I have changed batteries on my Rav4 on multiple occasions. One time notably, I removed the old battery and didn't put the new one in until the following day. I have never experienced any of your issues.
Did you try to jump the car before replacing the dead battery? Incorrect jumper cable connections may have fried something on your Rav4.
Also, have the new battery checked, as it may be defective. Inspect and clean the battery cable terminals and make sure that the earth cable has not been accidentally damaged / disconnected from the body.
Check this post to find out how you can read error codes using jumper wires on your diagnostic port:
Rough idle
and this file you requested on another thread:

 

[Akurat]

I have changed batteries on my Rav4 on multiple occasions. One time notably, I removed the old battery and didn't put the new one in until the following day. I have never experienced any of your issues.
Did you try to jump the car before replacing the dead battery? Incorrect jumper cable connections may have fried something on your Rav4.
Also, have the new battery checked, as it may be defective. Inspect and clean the battery cable terminals and make sure that the earth cable has not been accidentally damaged / disconnected from the body.
Check this post to find out how you can read error codes using jumper wires on your diagnostic port:
Rough idle
and this file you requested on another thread:

Thank you for your response. I have done this procedure many times either and I took a battery from my other car. It was used for one year, and it worked completely fine. I am almost sure that is in common with this computer relearn procedure, because, previously the car was driving just fine.

 

[Elle_Rav4]

Deleted

 

[Akurat]

I tried to put the old battery back (which was not dead, just very old.) I was facing same issues, actually, just because I plug off terminals.

About engine light: I am not sure now, because I did not take attention, but I think everything is as usual and if not what that could mean?

I did that old school diagnostics (Te1 and E1 connected with a jumper wire) and there are no faults according to the instructions.

Spark plugs are brand new like many things in this old car (According to the previous owner and the service history papers from Toyota dealership). I have an all service history of this car, so many things were done and the car is mint condition. At least it was.

I have cleaned the connections of the wires, even that there was no rust or dirt and didn`t check resistance anywhere (Do not have a meter at the moment where I am based). Thank you for your thoughts. I was looking for a simple solution, but it seems I`m not gonna get that one

 

[Elle_Rav4]

Deleted.

 

[Akurat]

Sorry, I am not a native English speaker, so you can easily find some barbarisms in my English if you are looking for them The problem started, when I disconnected ( not plugged off) battery terminals ( "+" "-"). Even when I put the same battery the problem did not go anywhere.

Engine light is on when I turn the key "ON"

There is no OBD2 port on my vehicle, that is why I used that old DLC port and a jumper wire for diagnosis. I did huge research in youtube, google this forum and another for a solution this week, but it seems that I am facing something unique I have an appointment in a workshop on Saturday, but I was hoping to solve it until then. I will buy a multimeter tomorrow and will do some checks.

 

[cRAVe]

I've disconnected the battery many times on my '97. I disconnect it if I'm going to touch anything electrical or even do work nearby something electrical. I've never had rough running problems after. The manual does say to make the front wheels straight, and turn off and remove the key before disconnecting the battery to deactivate the air-bags so I always do that.

Assuming that you have a left hand drive Rav4, there is a vacuum port on the passenger side of the intake manifold that is for the power-steering air-valve. Could you have knocked the hose off accidentally when changing the battery causing a vacuum leak?

 

[Akurat]

I am not sure. I have been in a workshop for a diagnosis and mechanic said everything is fine. He said that battery replacement and problem start is just a coincidence. I start to believe in that also. He recommended changing the fuel filter. Now I have to wait for a week to even get one. It is getting not fun to live isolated in Iceland