Car is shaking at certain rpm's and at a certain point in the throttle

[grinevb]

My car shakes pretty badly. I don't know at how many rpm, usually around 2k but it shakes at a certain point in the throttle as well. For example, if I'm barely at the throttle it will start shaking, but once I step on it down to the ground it will stop for the most part. I'm thinking injectors are bad/leaking. Any thoughts? I can post a video tomorrow.

[SoundEfx]

Check your motor mounts to make sure that they are in good shape.
Is your check engine light on?

[that1guywithans13]

Check spark plugs/wires, cap, and rotor. Also when you check the plugs make sure they are gapped correctly. The plugs can collect soot over time at the electrode and close the gap slightly which affects the way the car accelerates at light throttle which sounds what your problem is. Also check and clean your m.a.f. it sometimes but not as often has those symptoms.

[Mocha]

Try this: While car is parked idling remove the injector connector from 1 injector at a time and note the changes only for a few seconds on each, normally it should start to shake and whine. So basically if there is no drastic change on the suspected injector that means it's no good. Are they the stock injectors?

Removed connector and car whines and shakes: Good
Removed connector and there is little to no difference: No Good

So you might as well consider replacing the entire set anyways if they are bone stock and have lived a long life, when shopping you're gonna want to use this formula to calculate how many CC's do not go too far beyond the stock injectors CC but a little bit is ok.

(Example: KA24E SOHC @ stock is 260cc I replaced with 315cc and I'm ok). Higher cc = rich / lower cc = lean.. But my engine isn't exactly stock so I calculated that I'm good @ 315cc

(Engine Horsepower) x (BSFC) X (10.5)
--------------------------------------
(# of Injectors [4]) x (Injector Duty Cycle)