low idle celica

[mr2trd]

waddup. hey, my sis has a 90 cel ST with the original 4a-series motor...i believe....but it has extremely low idle speed. it doesn't idle low all the time, once every 5 secs or so, it'll drop below 500. so im thinking that one fuel injector is clogged, the fuel pump isn't running well, or something is wrong with the ignition system. i've even had it stall on me when backing up too slowly.

does anyone have an idea what this could be? the motor should still be good. im thinking the ignition, intake, or fuel system. thanks fellow cel-lovers.

[lloydjv]

Check to make sure that the TPS sensor on the throttle body is functioning normally. It may also be out of adjustment. Also check inside the throttle body itself to see if there is evidence of heavy carbon buildup. You can clean it out with carb cleaner and a tooth brush. It's best to remove the throttle body from ther intake manifold and clean the backside as well.

[Blane]

Manual or automatic.
I am guessing automatic, because it is your sister's car.

[mr2trd]

does it matter if it's auto or manual??? aite, if it does, obviously it's an auto.