My car is stuttering and shaking

[Tsunami]

Its stutters when i take off from a stop and now its stutters/shakes and rocks when i am at a stop. This went on about 6 months ago and then i changed my spark plugs and went away and it just started up again.

Any ideas of what it can be?

I have a 94 corolla, 150k miles.

Thanks!

[derf]

Ignition Control Module, Distributor Cap, Change the Plugs, Air filter, Fuel Filter, idle Control Motor, Vacuum Lines. Any one of those or a combination.

The ignition control module, distributor cap, and spark plugs are my first thought, shouldnt be more than $200 if you pay a mechanic to do it, half if you DIY. After that check the air and fuel filter which probably need replacing anyway, and I vaugley remember a weird shaped vac line going around the back of the engine that most mechanics would have replaced with a foot of regular vac line instead of the curves piece from the manufacturer, which causes it to rub instead of curving around a bracket.

[101lifts2]

^^^Just stick to Army stuff. LOL

IAC Motor has nothing to do with shuttering once the throttle is cracked open. Don't replace the ignition module, its not a component that wears out.

Replace the following with Either NGK or Denso parts:
1. Spark Plugs
2. Spark Plug Wires
3. Distributor Cap and Rotor

If the thing still shakes upon take off, you are going to have to take it somewhere to see if a specific cylinder is misfiring or if its random. It could be a bad fuel injector, bad coil, plugged converter, low compression on a cylinder etc. etc. etc. I would drive it, but you live too far away.

[Tsunami]

101, if I replaced the plugs and the wires 6 months ago, can it be bad already?

you don't think its the air filter? I just got my oil changed on Tuesday and they supposedly looked at the air filter and shook it out, and today especially when i came to a stop, it was just shaking all over the place!

Ugghh i hate not knowing anything about cars. I have the manual but its kind of hard to troubleshoot when i have no idea what to look for.

[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]

I would drive it, but you live too far away.

Totally missed that. Isn't Corona a couple of hours away? I remember driving by there last year and thinking, Oh 101 lives here! :lol:

[Tsunami]

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]

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.

http://i289.photobucket.com/albums/ll220/lontigger/tsuengine2.jpg

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.

[BobTheBiker]

let me ask something simple, that nobody else has. do you have a check engine light on the dash lit up? if so, have autozone pull the codes and see whats going on. THEN fix the problem rather than grasp at straws.

its possible that you have a bad engine mount, shitty spark plugs, maybe buy gas at a shitty station, have a vacuum leak, or several other potential issues. I'd start simple though and evaluate the condition of the vac lines.

[101lifts2]

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]

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.

http://i289.photobucket.com/albums/ll220/lontigger/tsuengine2.jpg

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.

[101lifts2]

101, if I replaced the plugs and the wires 6 months ago, can it be bad already?

you don't think its the air filter? I just got my oil changed on Tuesday and they supposedly looked at the air filter and shook it out, and today especially when i came to a stop, it was just shaking all over the place!

Ugghh i hate not knowing anything about cars. I have the manual but its kind of hard to troubleshoot when i have no idea what to look for.

No on the plugs, but it could be the wires IF the engine is actually misfiring. When you get on the gas, does the shaking go away? Like its only at idle?

Totally missed that. Isn't Corona a couple of hours away? I remember driving by there last year and thinking, Oh 101 lives here! :lol:

Las Vegas is about 3.5 hours away, unless I take a bike..then about 2. lol

[Tsunami]

let me ask something simple, that nobody else has. do you have a check engine light on the dash lit up? if so, have autozone pull the codes and see whats going on. THEN fix the problem rather than grasp at straws.

No check engine light.

[Tsunami]

No on the plugs, but it could be the wires IF the engine is actually misfiring. When you get on the gas, does the shaking go away? Like its only at idle?



theres a delay and a stutter when i get on the gas from the stop but yes it goes away once i start going.

The shaking / rocking starts again when i come to a stop and it got really bad at idle yesterday. It is intermittent though. yesterday it got pretty bad, today there isn't any rocking but there is still a sputter/delay when i first get on the gas.

Actually yesterday after all the rocking and such at one point (and it was a bit cooler during the day, don't know if that makes a diiference) when i started it up to go home, i got on the gas and at about 30 mph and there was a surge and all of a sudden it was smooth again for the next 3 miles until i got home.

Checked the air filter, it looks pretty good. none of the wires seem to be loose. I put decent gas in it, either at the Chevron, Shell or Circle K. Oil and tranny fluids seem good.

[BobTheBiker]

Might not hurt to clean the trottle body, and do a fuel filter. my aunts kia sportage does this at idle too, although I just dont give a shit cause tht thing leaks oil and needs 4X more work than its worth.

[Amber Lamps]

I still like the vac lines or the fuel filter.

[Flexin]

Where is the mass air flow sensor on this car? If its near the air box I would check for the intake pipe after the sensor. Look for cracks or breaks in the pipe. This will allow air in that isn't measured by the mass air flow sensor which would cause it to act up. In some gears it could remain closed and cause no problems. In the lower gears you can have a lot of movement with the engine, this can cause a break to open up and let in more air.

James

[derf]

I still like the vac lines or the fuel filter.

I just fixed my focus for a similar issue, eventually I found 2 vaccum leaks, one vac line wad a solid hole, because the tube was dry rotted and cracked, replaced that, but then the studder was still there randomly, eventually I was able to find that the valve cover breather was off the valve cover and enough gook had settled on the vac line to make it rub and wore through, but the grease was caked on thick enough that it would seal the vac line causing it to be an intermittent problem.

[Amber Lamps]

I just fixed my focus for a similar issue, eventually I found 2 vaccum leaks, one vac line wad a solid hole, because the tube was dry rotted and cracked, replaced that, but then the studder was still there randomly, eventually I was able to find that the valve cover breather was off the valve cover and enough gook had settled on the vac line to make it rub and wore through, but the grease was caked on thick enough that it would seal the vac line causing it to be an intermittent problem.


That's where I'm at myself.

[Tsunami]

I'm stalling doing chemistry hw so I am digging up old posts :lol:

Problem has been fixed. A fellow rider out here is a mechanic and fixed it.

Found out new wires weren't put in last time.

So he changed the plugs with NGK, wires, cap, ignition roter and fuel filter. He doesn't think the fuel filter's even been changed :lol:

[Rangerscott]

Might as well change the air filter too.




P.S. You gotta change your avatar. I feel as if I'm really talking to your pug.

[Tsunami]

Might as well change the air filter too.




P.S. You gotta change your avatar. I feel as if I'm really talking to your pug.

And I am talking to your headlight.

[azoomm]

Might as well change the air filter too.




P.S. You gotta change your avatar. I feel as if I'm really talking to your pug.

Knowing Gina, and Puggy, you are. :lol:

[101lifts2]

I'm stalling doing chemistry hw so I am digging up old posts :lol:

Problem has been fixed. A fellow rider out here is a mechanic and fixed it.

Found out new wires weren't put in last time.

So he changed the plugs with NGK, wires, cap, ignition roter and fuel filter. He doesn't think the fuel filter's even been changed :lol:

A wire trick is to spray them down with Windex and run the engine with the hood open and look for sparking.

Just make sure the valve cover isn't full of oil. :lol

[racedoll]

Knowing Gina, and Puggy, you are. :lol:

Yep, exactly what I was thinking.

Glad you got your car fixed. Now go to your chemistry!