pearlywhite90ls

I have a 1990 ls 400, since i got the car, the ignition cylinder has been a little tricky as the key doesnt slide in smoothly, yesterday i tried to start the car but the key wouldnt turn, eventually i got the key to turn to "on" but not to "start". I do live in michigan and it has been colder this past day, please any advice would be greatly appreciated. also i have been driving without power steering for a few months i dont know if that could have created this problem

is it possible to adjust my tps by my self? also is it possible to clean my iavc (im not really sure what that is) ? thank you

i have a 1990 ls 400. when my car sits for more than about three hours the idle is very rough and low. when i start the engine it lasts for about 45 seconds the the idle will shoot quickly up to is normal idle of 600 if i attempt to accelerate before it reaches its normal idle the engine almost stalls out. also when i come to a quick stop the engine will some times stop, i also have noticed that the idle is higher when i leave th ac on. could this have something to do with me tps sensor or my valve cover seals? if any one has experienced these problems and has been able to correct them please inform me on how toi do so. thank you

I am the owner of a 90 ls 400 and have been experiencing some idle problems. to start, when i dont start my car for any longer than about 3-6 hours, before it warms up, the idle is extremely rough and rpms very low almost to the point that the car stalls. i have a feeling this could be old valve cover gaskets. if any one has ever experienced this problem and/or has replaced these gaskets please give me any tips on the project. i consider my self to be a little below experienced and could use any advice available. also when i come to a quick stop my car will sometimes stall could this be related if so let me know... thankyou