My car is stuttering and shaking

[Amber Lamps]

I want to say cracked vacuum line or bad spark plug wire. I know you said that you are not mechanically adept but with the car running try spaying some carb cleaner around the vac lines and see if this affects the motor idle. It seems that there is a vac module that controls idle/fast idle on these cars. The fact that it's getting progressively worse suggests something along these lines. Also because the engine was just fiddled with during your oil change may have exacerbated the condition. If you're lucky, you just have a crack on the end of a line which can be cut off and re-attached. I wouldn't run out and buy a bunch of parts just yet. Also, the fuel filter or even the fuel pump are suspect in my mind. For your own piece of mind, try taking out the air filter and see if it affects the condition. You have nothing to lose but a few minutes of your time.

[Tsunami]

Originally Posted by TIGGER

I want to say cracked vacuum line or bad spark plug wire. I know you said that you are not mechanically adept but with the car running try spaying some carb cleaner around the vac lines and see if this affects the motor idle. It seems that there is a vac module that controls idle/fast idle on these cars. The fact that it's getting progressively worse suggests something along these lines. Also because the engine was just fiddled with during your oil change may have exacerbated the condition. If you're lucky, you just have a crack on the end of a line which can be cut off and re-attached. I wouldn't run out and buy a bunch of parts just yet. Also, the fuel filter or even the fuel pump are suspect in my mind. For your own piece of mind, try taking out the air filter and see if it affects the condition. You have nothing to lose but a few minutes of your time.

I have no idea what a vacuum line is or where my air filter is...I guess the manual and I will be spending some quality time together.

I could ask the creepy asian guy that lives 5 feet away from me, he owns a shop around the corner and gave me his card. But he's creepy...and he may want to put a big spoiler on the back of my car and a bobblehead on my dashboard.

[Amber Lamps]

Originally Posted by Tsunami

I have no idea what a vacuum line is or where my air filter is...I guess the manual and I will be spending some quality time together.

I could ask the creepy asian guy that lives 5 feet away from me, he owns a shop around the corner and gave me his card. But he's creepy...and he may want to put a big spoiler on the back of my car and a bobblehead on my dashboard.

Haha! That's a good one! The thing is baby, you will NEVER become capable of working on your own car until and unless you try! You have to start some where! If you lift the hood, the vac lines are small, black hoses that generally run from the fuel injection system.



On this picture, the guy has painted his "air box" red. It is on the right and is the piece with the large hose/tube coming out of it. The cover is usually held on with a few screws or clips. The clips can be popped with a screwdriver or even a butter knife. If you follow that "hose" to the left, you'll see that it connects to a "valve" which is the throttle body. The throttle body has a couple cables coming off of it and some small hoses which are vacuum lines. From there it goes to the fuel injection system which is that "box" to the left. Also, if you look at the top of the engine, you'll see four wires coming out of it, which are the spark plug wires. I want you to visually inspect them for any cracks and see if they are possibly loose where they plug in to the engine or at the ignition module (the black box between the air box and engine), it's unlikely that your car has a distributor cap. Just make sure that they aren't loose or obviously cracked.

If you are feeling really brave, the throttle body has an idle adjustment screw that can be turned to speed up your idle and possibly end you problems. If you look at the throttle body closely, you will see that the cables are attached to a "wheel". The screw controls where the "wheel" stops when the cable is released which controls how fast the motor runs when you aren't pushing the pedal (idle). Now all you have to do is turn that screw 1/4 turn clockwise increments and see if you situation improves. I would do this with the car running but if you are uncomfortable with that, just turn the screw a 1/4, start the car. If it's better good, if not try again. I would not go over one or two full turns. If this doesn't help, I'd try your Asian friend. The steps I have outlined to you are basic and will not harm your car in any way. If adjusting the screw doesn't help, keep track of how much you turned it and just put it back.

[Phenix_Rider]

My guess would be the engine mounts. At that age, the rubber in them is probably disintegrating. A lot of front engine cars will have a mount that goes over or under the radiator to prevent fore/aft rocking. Since that's the way the engine rotates, it can make a lot of noise.

[101lifts2]

Originally Posted by Phenix_Rider

My guess would be the engine mounts. At that age, the rubber in them is probably disintegrating. A lot of front engine cars will have a mount that goes over or under the radiator to prevent fore/aft rocking. Since that's the way the engine rotates, it can make a lot of noise.

I was under the assumption the engine more or less runs like crap and misfires, but it could be motor mounts. I just replaced both on my buddies wife's Ford Focus...thing shook like a bitch.

[101lifts2]

Originally Posted by TIGGER

Haha! That's a good one! The thing is baby, you will NEVER become capable of working on your own car until and unless you try! You have to start some where! If you lift the hood, the vac lines are small, black hoses that generally run from the fuel injection system.



On this picture, the guy has painted his "air box" red. It is on the right and is the piece with the large hose/tube coming out of it. The cover is usually held on with a few screws or clips. The clips can be popped with a screwdriver or even a butter knife. If you follow that "hose" to the left, you'll see that it connects to a "valve" which is the throttle body. The throttle body has a couple cables coming off of it and some small hoses which are vacuum lines. From there it goes to the fuel injection system which is that "box" to the left. Also, if you look at the top of the engine, you'll see four wires coming out of it, which are the spark plug wires. I want you to visually inspect them for any cracks and see if they are possibly loose where they plug in to the engine or at the ignition module (the black box between the air box and engine), it's unlikely that your car has a distributor cap. Just make sure that they aren't loose or obviously cracked.

If you are feeling really brave, the throttle body has an idle adjustment screw that can be turned to speed up your idle and possibly end you problems. If you look at the throttle body closely, you will see that the cables are attached to a "wheel". The screw controls where the "wheel" stops when the cable is released which controls how fast the motor runs when you aren't pushing the pedal (idle). Now all you have to do is turn that screw 1/4 turn clockwise increments and see if you situation improves. I would do this with the car running but if you are uncomfortable with that, just turn the screw a 1/4, start the car. If it's better good, if not try again. I would not go over one or two full turns. If this doesn't help, I'd try your Asian friend. The steps I have outlined to you are basic and will not harm your car in any way. If adjusting the screw doesn't help, keep track of how much you turned it and just put it back.

You really shouldn't tamper with the min. idle set screw on fuel injected cars. I know that Mazda had issues with their early 1990's Protege's. We would bump it up to 700 cause the idle was pretty shitty on some, but there was no other fix nor was there an issue with the vehicle. Usually, cleaning the throttle body would do the trick. Also, I doubt an air filter is going to do anything. But as periodic mantenance, it should be changed at certain intervals, though.