Need advice for some problems on my 91 mk3
 

well i guess theres more than one..

first:My idle...i start the car it starts going up and down and all of a sudden the car shuts off..this happens on and off..

second: my ebrake light turns on and off while driving...never happened before.

the idling is my worst issue at the moment considering the car is shutting off on me while im on the road sometimes..im driving and i stop the idle starts to drop and it shuts down and i have to restart it...when the AC is on it goes up but still this problem is occurring any ideas? please reply if u know of anything

My first guess on your idle is that you have leaking/broken/misrouted vacuum lines. The brake light is most likely due to low brake fluid.

Also, a little more info may be helpful. Is this a turbo or N/A? Auto or 5 spd? Also, have you checked for any CEL codes?

The erratic idle could also be cause by a misaligned TPS or a failing IDL switch within it. A code 51 while the car is at idle will give that away. AFM is another possibility.

I'd start with checking for stored diagnostic codes: http://www.cygnusx1.net/Supra/TechTi...ror_codes.aspx

This is a twin turbo auto, Ok well thanks for the break fluid help i got rid of that problem...this may sound stupid but is the electronic antenna replaceable?

Which engine? 1G-GTE, 1JZ-GTE or 2JZ-GTE? In all of these cases I believe the airflow is determined through the measuring of manifold pressure via a vacuum hose... in which case btwilson86 is dead right, a bad vacuum hose is a very likely culprit.

Okay thank you i will get my mechanic to check it out this is a 1jz GTE engine.