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Corolla 4zz idle

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Well lads, 

Ive got a 1.4 vvti corolla e12 with some idle issues at cold start its idle is around 950rpm and warm idle is dropping down to about 500 to 600rpm, i have replaced the throttle cable as the old one was overstretched and also replaced the throttle body and cleaned the maf sensor, car had a full service but i cant seem to get it to idle right, when its warm and i let the foot off the clutch instead of the car starting to move its nearly cutting out on me, its not the clutch as that was replaced 3k miles ago, car has 163k miles any help much appreciated

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Check for air leaks on all the hoses and see the air filter fits tightly.

Next try this:

1. Switch the key to position two

2. Switch off to position zero and wait 15 seconds

3. Switch the key to position two and start the car for a 20-30 min drive (to work or the like) - the throttle position should reset to normal when you come to rest a few times... if not persist driving (do not switch engine off) and it will eventually reset itself to normal after idling for 5 mins or so after about 30 mins.


What did you clean the MAF sensor with? If you've used Carb cleaner it will likely have destroyed it's integrity. You'll need to replace it.

Has the throttle stop screw been adjusted? If not, do not alter this...

If you replaced the whole throttle body, chances are the TPS is faulty. Replace this with the correct part and see if it resolves the problem.


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I cleaned the maf with nothing but a wipe of a dry cotton bud as i had run put of carb cleaner doing an egr valve on a mates e12, i changed the tps when i replaced the throttle body.. Only reason for changing the tb was that the old cable was proper living in the tb and i broke the plastic bit getting it out no leaks in any of the hoses apart from the one coming from front bumper into the airbox which i removed as there wasnt much of it there to begin with


Had it out for a good run the other day but didnt take notice if the idle sorted itself im so used to giving a little extra throttle to take off at this stage



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