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TJ magna wont idle after battery replaced

Posted: Mon Nov 08, 2010 10:47 am
by Guy
My wifes TJ magna's battery was on it's way out so was replaced with a new one. Afterward it wont idle when warmed up.
I gather it is something to do with the Idle up solenoid (or whatever it is called) or the throttle position sensor .. (or the computer has lost its base settings after being unpowered for a few minutes)

So mighty mighty outers oracle .. .help will it relearn or is it a dealer\plug into a computer job ?

Re: TJ magna wont idle after battery replaced

Posted: Mon Nov 08, 2010 12:23 pm
by chris_stoffa
Disconnect the battery again, wait 30 mins and reconnect
My dashboard & computer went silly after I changed battery so that was how i sorted it out.

Might work for you

Re: TJ magna wont idle after battery replaced

Posted: Mon Nov 08, 2010 1:09 pm
by Guy
Havent got anything to loose ...
Will give it a go.

Re: TJ magna wont idle after battery replaced

Posted: Thu Nov 11, 2010 12:38 pm
by millert85
u'll have to take it to mistu and get the base idle reset. theidle stepper motor runs out of adjustment and can't compensate. the dealer has to plug the scan tool in and reset it then adj the manual idle bypass screw. as a stop gap u MAY be able to wind the screw up to get it drivable, but will idle thru the roof. best bet it left foot brake and drop back to N. last time i got it done cost me $60 for the 5 mins it took... dodgy bastards. and u can rest the computer in 5 secs by disconnecting lead and pumping brake couple times, drains the capacitors in ecu some how.

Re: TJ magna wont idle after battery replaced

Posted: Thu Nov 11, 2010 2:47 pm
by Josh n Kat
you actually just need to clean the throttle body.
over time they compensate of a gummed up throttle body and stepper motor and when you replace the battery it goes to the factory base mode.

Just pull the intake piping off and give it a good clean with carby cleaner and a rag and it should be fine :armsup:

Re: TJ magna wont idle after battery replaced

Posted: Thu Nov 11, 2010 4:59 pm
by chunks
Make sure the airflow meter is plugged in.

Re: TJ magna wont idle after battery replaced

Posted: Thu Nov 11, 2010 7:03 pm
by Modified Toy
This happens all the time at work after we have replaced transmissions, remove the stepper motor and clean with carby cleaner and clean the throttle body also, usually the stepper motor gets stuck because when you connect the battery after it has been disconnected the stepper motor winds all the way out and gets stuck and causes low idle.

Re: TJ magna wont idle after battery replaced

Posted: Thu Nov 11, 2010 11:24 pm
by DUDELUX
Mrs Ds Pajero has just started a very similar problem.
It idles really low, and stalls out sometimes, it idles at about 300-500rpm, and sometime lower and just stalls.
It happens to her a bit whilst braking or turning corners.
Is it just a simple turn the idle screw or is there something else I should be looking at too??
I will look inside the intake hose as posted above.

Re: TJ magna wont idle after battery replaced

Posted: Fri Nov 12, 2010 8:01 pm
by coilcab
wind idle stepper motor anti clock wise untill it idles at about 2000rpm and then slowly wind it back in until desired rpm.

Re: TJ magna wont idle after battery replaced

Posted: Fri Nov 12, 2010 11:51 pm
by Guy
it seems to be a bit better .. but still idles low, I will give these things a try and tell you which one works .. I have an entore spare low k thottle body, stepper, TPS etc I got when I got my new motor for my pajero TL motor (I think) so ca nswap a few of them about to.

Re: TJ magna wont idle after battery replaced

Posted: Sat Nov 13, 2010 10:19 am
by 80cruzza
This same thing happened to a girl i work with after battery world changed the battery, she took it back there and they did a "relearn" something bout turning ignition on and off at differnet times, Dont know if you have battery world over east but might be something to try? I will ask her monday what they did and see if she remembers.