Idle Has Started To Go Lumpy Randomly

May 12, 2009

Hi guys,

A few years a go I ditched the germans (bmw) and decided to go jap (toyota). I was weiry at first but I have to say my ST183 has been fantastic for the last 3 years or so. Only light maintenece and a few tyres changed and it just keeps going.

But recently it feels as if it has started to show its age.

What has started happening recently is that I can drive for a good 45mins to an hour but then randomly at lights or when im stopped it will feel a little lumpy and then the revs just seem to fluctuate from 500 to about 2000, as if it was drowning. At first I thoght it was going to switch off, so id press the accelerator a bit in order to keep it running, sounded as if it was going to choke but then it would clear up and I could rev normally for a while. The next couple times it happened, I just left to see if it would turn the engine off, but it didnt and it manages to sort itself out.

So to summarise that, car is fine until I drive for a while and then "randomly" as it doesnt happen everytime I stop, the revs would run lumpy and go up and down for a few secs and the it would clear itself.

Speaking with a few people I was told to try the old easy steps first, so I did a home service, I changed the sparks, new element in air filter and checked all the pipes and stuff and it all seems ok, I even cleand the butterfly to. And for a while it ran even better, but then the other day it happened again. Im not sure what else to try.

So I was wandering if any of you guys have any ideas what could be causing this or any tips on were to start looking anything.

Any help would be very appreciated and thank you in advnce.

May 12, 2009

Do you have aircon on the car, if you do it could be this cutting in/out.

May 12, 2009

yea it does have air con, but havn't used in a very long time, and I normally have to trigger it to start with the a/c button, is there any way to possibly check if it is that?

May 13, 2009

If you turn the air con off this should not then interfere with the idle speed.

May 13, 2009

Hi guys,
A few years a go I ditched the germans (bmw) and decided to go jap (toyota). I was weiry at first but I have to say my ST183 has been fantastic for the last 3 years or so. Only light maintenece and a few tyres changed and it just keeps going.
But recently it feels as if it has started to show its age.
What has started happening recently is that I can drive for a good 45mins to an hour but then randomly at lights or when im stopped it will feel a little lumpy and then the revs just seem to fluctuate from 500 to about 2000, as if it was drowning. At first I thoght it was going to switch off, so id press the accelerator a bit in order to keep it running, sounded as if it was going to choke but then it would clear up and I could rev normally for a while. The next couple times it happened, I just left to see if it would turn the engine off, but it didnt and it manages to sort itself out.
So to summarise that, car is fine until I drive for a while and then "randomly" as it doesnt happen everytime I stop, the revs would run lumpy and go up and down for a few secs and the it would clear itself.
Speaking with a few people I was told to try the old easy steps first, so I did a home service, I changed the sparks, new element in air filter and checked all the pipes and stuff and it all seems ok, I even cleand the butterfly to. And for a while it ran even better, but then the other day it happened again. Im not sure what else to try.
So I was wandering if any of you guys have any ideas what could be causing this or any tips on were to start looking anything.
Any help would be very appreciated and thank you in advnce.

Might be some engine sensors that control idling. Maybe the lambda and/or airflow sensors on their way out or even dead.