Toyota Repair: 2001 Celica GT idle problem, celica gt, vacuum line

Question
Hi I just purchased a 01 Celica GT.  Love the car but sometimes after driving the tachometer goes from 1 then almost stalls at 0 then back to 1 back to 0 then 1.5 eventually it will idle at the 1.5 Now this only happens when I'm in nutural as my car is a 5 speed.  Is this a common problem?  Any suggestion from you would be a great help to me.  I see you really know your stuff.  Thank you in advance for your help.

Cheers,

Tim :)  

Answer
I am prone to think one of the following:
1. Either there is a plugged vacuum line or a kinked one somewhere. I am assuming that since you say after driving it reacts this way, that the car is at operating temperature.
2. I would take a look at the connections around your throttle and look for a broken or disconnected spring. There is also a a cap with a little filter on it next to the throttle body. There should be a vacuum line running into it. Carefully pull the cap off and make sure the filter is not plugged. Again make sure your vaccum lines are not plugged and also make sure your air filter is clean too.