shakes when you press on the gas and it's not the balancing or aliginment what do you think it is...

There's not much info here-could it be tune-up related?

I presume you mean that when you accelerate normally, there is an unusual vibration. I'll throw some basics out there. I like to listen at the exhaust pipe with the engine running, to see if I can hear any irregularity in the engine's running. The sound should be a smooth, even putter. When an engine runs poorly, with irregularities or roughly, then the first thing I would do is replace the rotor, distributer cap, spark plug wires and spark plugs, change the oil and oil filter, and give it a fresh air filter. I'd check all the other fluid levels (transmission, brake, coolant...). Now that pretty much exhausts all I know about engines, no pun intended. :loser: If you've done these things already, or if your car's problem clearly lies elsewhere, sorry to take up your time. But if you mean that, as you cross over the 100 mph mark, the car rattles a bit, that's a different question altogether. :evillol:

I'd say what it could most likely be is a warped brake disc. Check the discs, and you might want to take them to a shop somewhere to see if you can have them spun. Or you could go the easier but more expensive way out by replacing the discs and all of the other things that parmenides3 listed. It could be either or. Check it out, and let us know.

my car shakes when you press on the gas like
say u are going about 30 mph and u let go of the gas then it rides smooth but when u accelerate it starts to shake agian i don't know what it is.

You can test it for a bad motor mount by opening the hood,have someone in the car put it in gear-foot on the brake,and give the car some gas,then let off,some gas then let off,ect.If a mount is bad the engine will move an abnormal amount.

Also, in addition to the motor mounts, it's also possible that you could have a bent axle assy, warped brake disc, worn inner and or outer CV joint, out of round tires, and over or underinflated tires. You'll want to check all of these things first...

Check if all cylinders work. If it's a 4 cylinder, it worth a try.

You can just pop up the plug wire caps, keep them in place, start the engine, and pull up each wire one at a time. This will disconnect the wire from the plug. If that cylinder is good, after the wire is up, it stops working and your engine will chatter badly. If there is nothing happen when you pull up a wire, that cylinder is dead. Remember to put the wire back before you pull another one.

If a cylinder is dead, your best bet is the wire or the spark plug.

Did you ever find out what caused the shake in your car. I had the same thing start to happen in my girl's car today. same make and model.

Could be a bad injector. Been there, done that. Needed to pull the injectors and clean them in solvent.

Gen 3's shake because the front mount goes bad quickly, due to extra heat from 5SFE engines and the design of the mounts (to accommodate vibration). Once the front mount gets loose, the bone mount (on top of the engine) cracks and falls apart, which causes the engine to rock back and forth more than usual, which puts extra stress on the tranny, which causes the axles to bend, CV boots to deteriorate, and brake rotors to warp.

Get new mounts first and use new bolts on the front mount, then get the tranny checked to see how off the axles are ($300 repair for both axles to be replaced at ANY non-toyota shop), get your rotors resurfaced (don't need to be replaced) and just in case, replace the tranny mount, and it should stop.