My car shakes like crazy when idle?

[marybearr]

When im stopped on a red or whenever im stopped and my car is at neutral, my car starts to shake pretty hard. Whats wrong?
It also shakes when i drive over 75 mph, but i dont think thats a big deal because most cars do that, but im worried about the shaking when im stopped.
My car is a manual 1990 Nissan 240sx.
Thanks

[Strugglebucket]

Sounds like a miss. Be extremely careful with the following: Start the car and pull one spark plug wire at a time, then replace. If one cylinder has little to no effect on the idle, that would be the suspect cylinder. Hopefully this will point you in the right direction. While there are plenty of suspects, like MAF sensor or timing, I assume the car is in good running condition so I'd check that. Good luck!

[Mercury_Hg]

Couldn't it be the IACV, too? I'm new to all this, but I remember something about rough idling and the IACV.

[AHall]

You may also try unplugging each injector. If you get to an injector that does not cause a noticeable difference when it is unplugged, then the injector is bad.

[Strugglebucket]

Both very good suggestions. Do you smell fuel in the exhaust by chance? "Putt-putt" coming from the muffler?

[marybearr]

Thanks guys Im going to try working on it today and see what happens. I dont smell any fuel at all, its just shaking. If I drove around with it like this could it destroy my car if I dont do anything about it? Or if I need to go somewhere, would it be a big deal if I drove around with it a little? Its perfectly fine when its in motion.

[benarovi561]

Thanks guys Im going to try working on it today and see what happens. I dont smell any fuel at all, its just shaking. If I drove around with it like this could it destroy my car if I dont do anything about it? Or if I need to go somewhere, would it be a big deal if I drove around with it a little? Its perfectly fine when its in motion.

check the motor mounts. rev it up when it shakes see if it misfires...

[marybearr]

Alright so I removed each spark plug one by one and it looks like one of my cylinders isnt firing because when I took the 3rd spark plug out it didnt make a difference in my engine. So I got new spark plugs just in case that was the problem and unfortunately it wasnt :/
My neighbor took a look at it and he says its probably the fuel injector. I honestly have no idea how to change that?
My distributor cap is also all burnt out, so could that be it as well?

[Mercury_Hg]

Alright so I removed each spark plug one by one and it looks like one of my cylinders isnt firing because when I took the 3rd spark plug out it didnt make a difference in my engine. So I got new spark plugs just in case that was the problem and unfortunately it wasnt :/
My neighbor took a look at it and he says its probably the fuel injector. I honestly have no idea how to change that?
My distributor cap is also all burnt out, so could that be it as well?

Did you test each spark plug to see if they're sparking?
Absolutely do this first.

If the third spark plug isn't sparking still (even though it's new), it's probably either the spark plug wire, or distributor cap / rotor. As far as I understand it, anyway. I'm new to this stuff.

[AHall]

you should have checked the injectors

[marybearr]

you should have checked the injectors

Yeah im gonna try replaceing that and see if it works