Car shaking?

[atomicradish]

Been a long time since I posted here....a problem with my car is what has brought me back.

Recently my car started shaking when I accelerate. The problem started happening all at once, not gradual at all. It shakes vehemently in every gear, primarily during acceleration, but also to a lesser extent if I am simply pressing the gas pedal. In the limited driving I have done with the car, I've resorted to a lot of gas saving techniques like neutral coasting and EOC, because this is the only way to really reduce the shaking. The shaking does appear to be slightly lessened if I drive the car in a lower gear and thus a higher RPM. This problem has also significantly impacted the performance of the car. For instance, it has difficulty maintaining highway speeds in 5th gear, and acceleration is impaired. Additionally, the car is idling poorly. The tach jumps up and down between 600 - 1000 RPMs. Perhaps it is just anecdotal but it seems to idle WORSE after the car has warmed up.

Any help you guys can give would be greatly appreciated. I just got a new apartment and have a lot of expenses, so my hands are really tied in terms of professional help. I am hoping someone here can help me diagnose it, and I can get a manual and fix the problem myself.

And in case it helps, it is a 1994 Mits Galant.

Thanks!

[Daox]

The jumpy idle sounds like a vacuum leak. Less likely would be a sticky IAC valve.

As for the shaking, is the check engine light on? With the reduction in power it almost seems as though you've lost a cylinder. I'd check that all your spark plugs are firing. If they all are, I'd check compression. With all the shaking, I'd also take a look at the engine mounts.

[nabowen]

there's a good possibility you have bad plug wires. They usually cause misfires at app. 1800 to 21 or 2200 rpm under light acceleration, light load. nabowen

[RandomFact314]

My car shakes like a freaking tank & I drive a dodge neon >.<
I am 80% sure I have a vacuum leak & I also have a broken engine mount...
check those 2 things...

[RandomFact314]

ACTUALLY, if you figure out what is wrong with your car PLEASE PLEASE PLEASE tell me what is was and how much it cost b/c I read the rest of your post and mine is doing all the same things...

it acts CRAZY between speeds 55+
the idle is crap, it jumps and dips
my cruise control randomly turns off
my car shakes (partly b/c of the broken mount)

so does it really sound like a bad vacuum line?
how much is that to fix?

[bestclimb]

Originally Posted by RandomFact314

ACTUALLY, if you figure out what is wrong with your car PLEASE PLEASE PLEASE tell me what is was and how much it cost b/c I read the rest of your post and mine is doing all the same things...

it acts CRAZY between speeds 55+
the idle is crap, it jumps and dips
my cruise control randomly turns off
my car shakes (partly b/c of the broken mount)

so does it really sound like a bad vacuum line?
how much is that to fix?

If you have a vacuum leak open the hood with the engine running and you should be able to hear the hiss. once you locate it it will cost a couple bucks for the right size vacuum hose to replace it if needed.

[RandomFact314]

Originally Posted by bestclimb

If you have a vacuum leak open the hood with the engine running and you should be able to hear the hiss. once you locate it it will cost a couple bucks for the right size vacuum hose to replace it if needed.

Is there any way it could be the line that does my cruise control?

[bgd73]

1994, and a mitsubishi

try struts.

I have found that to be a problem. vibration has bearing smacking, shaking and seemingly normal otherwise is something else.

[ktuuri]

I would look at the easier things first, like some of the other posters say.
I would think it might be a plug wire off or a defective sparkplug. But if that seems alright, take a better look at your distributor. If that checks out, you may be looking at a timing belt or chain.

[wagonman76]

Sounds exactly like what my van was doing when it had a bad spark plug wire. A bad spark plug or coil can do the same thing.

My Celebrity did it once too right after putting in new spark plugs. Turned out 2 of the new plugs had cracked insulators. NEW new plugs, and the problem was gone.