When I go to start it, it doesn't want to start (it just grinds, like it's not getting gas; it will not fire). After about the third try, it'll start, but it idles really low until I give it gas. This was only happening once or twice a week. However, I've noticed that it is happing more frequently. Any ideas?
Is grinding normal cranking noise, but no start? If it is it could be a fuel pump check valve not holding and causing no fuel pressure. Next time it cranks and doesn't start, turn the key to run and you should hear the fuel pump turn on. When the pump kicks off, in abount 15 seconds, turn the key off . Repeat 2-3 more times. If it is a fuel pressure problem, this will prime the system.
I'm not sure if the Avalon has this problem, but I, and many other Toyota drivers I know, have gotten soaked charcoal cannisters. I don't know why this isn't a recall issue. Try mashing the accelerator pedal down when you start it. Also, get a multimeter and test the ohms on your purge valve and idle control motor. get a manual or search Toyota forums for the resistance values for your model. Take it to Autozone and they will put an OBDII reader on it and give you a list of codes.
Hope this helps - I'm looking at throwing down around $400 for this same problem. If you find emissions parts somewhere besides the dealer please let me know!
__________________ "Aw! Why does everything that only happens to stupid people happens to me?" - Homer J. Simpson