i have a 94 camry with 135k miles on it. two week ago i tried starting up my car, the engine wouldnt turn (no sound at all). then right after i tried starting up again, the car started with no issue. then a few days later the problem started again, but the car starts up but the rpm sinks below 500 but the car idles fine if i press on the accelerator above 1k rpm for 30 sec or so. i've had this problem fixed before at my mechanics 4 months ago, spending over $300 to fix it. this time around, i dont feel like spending another $300 to fix it, so i would like to know where to look at when i attempt to repair it.