help, speratic brake issues and throttle-off-idle issues.

[94tegRS]

OK, before you start reading I know it is long but its very important cuz my girls dad wont let her go to mexico with me on christmas unless I get this fixed, and I dont wanna take it down there without it being fixed anyways so please help, it is greatly appreciated if you do.

ok, I bought a 1990 camry with 97k on it about 6 months ago, was VERY clean, its from my uncles friends mom who had it since new. I drove it from boston, MASS, to hoboken, NJ, then to washington state(not DC) where I live, made the thousands of mile journey no problem, and ive since put on another 5-6k on it with no problems, since about the first day I got it home it did do one weird thing though, stop at a stop sign or something and the car would come to a stop, keeping steady pressure on the brake pedal to stay stopped(its an auto, also its the 2.5 V6 just so you know) the pedal would sink a bit, not to the floor but just about 2-3 inches and then stop there and still hold the brakes. I have NEVER added a single drop of brake fluid to the master and its still at max like it was so I know it doesnt leak. then the problem progressed into everyonce in a while, as you were braking the pedal would lose its feel and youd have to "chase" the pedal down those few inches til the brakes would grab again. pedal would have the same feel just not the same positioning. did this for a while and then it did the first two plus a new one. when idling at a stop sign, sometimes when you hit the gas it wants to die for a second. like it chokes itself out and then goes, so quick takeoffs werent an option cuz you might end up sputtering along in front of moving trafffic for a second. now I was thinking vaccum at this point like maybe it had something to do with the vaccum boost on the brakes and the vaccum to all the sensors for idle control. it didnt bother me enough to fix it at that point but now its really scary to drive. sometimes when you hit the brakes, you press hard and nothing happens til the front left locks up, then it will go back to normal, then sometimes when you hit the brakes it just wants to throw you off the road to the right, then to the left again. also when the brakes feel like they are not working I pull the ebrake and feel the rears engage. and at a stoplight how normally you can repeatedly tap the brakes to hop the front end in an auto, well mine doesnt hop, it dives left hops up to the right and then the brake sends it left so obviously at this point the fronbt left is the only function brake... up front at least. and obviously sometimes the rears dont work. could this be a problem with my porportioning valve?
I was thinking a caliper might be sticking but wouldnt that be more of a steady problem instead of being so inconsistent? I am going to replace the rear pads soon cuz when I pull the e i can hear it grind, I know it wont fix it but I am gonna check if anything looks wrong back there and take off the fronts just to inspect the calipers visually to see if anything catches my eye. then maybe a new porportioning valve or something.

I was thinking maybe a particle of something was in the valve blocking differetn passages at different times maybe. would it be a good idea to remove the calipers and wheel cylinders and master and valve and clean everything and blow everything out with air and then re-bleed it all and see if it helps?

thanks alot for the help. I need to get it fixed by dec. 16th cuz im driving it to mexico.

not so concerned with the idle ill deal with it later just threw it in there in case anyone thinks its related.

[Daniel M. Dreifus]

If the brake pedal is sinking to the floor that points to a problem with the master cylinder.
Rebuild or replace

[94tegRS]

it doesnt sink to the floor, just a couple inches and just sometimes, and that couldnt make certain wheels work at certain times could it?

[KimMG]

Flex brake lines deteriorate internally and can restrict the flow of fluid to the calipers. Waiting until the brakes grind before servicing or replacing worn parts can add to the cost of repair. Do you have a local brake shop that does free inspections? Check for any stored trouble codes. Be aware that the shoes for the parking brake may only be a dealer only item and costly.