car runs, but not the way it should

[lrall]

i have a 2002 taurus SES. I go out to start my car last night and it fires right up but the whole car SHAKES, it vibrates teh whole car bad enough for me to notice it. It also has an idle problem, the idle is almost lumpy. it doesnt die but sounds like one of the cylinders isnt firing, has anyone had a similar problem or have any advice

[shorod]

Could be exactly like you suspect, a cylinder (or more) could be missing. You might have a bad spark plug, bad plug wire, plug wire being shorted out, stuck injector, bad injector wiring, vacuum leak, bad head gasket, and probably a few other things I'm not thinking of.

You'll need to do some more investigation to find out if it's electrical, fuel, or vacuum related. You might start by pulling plug wires one at a time to determine which cylinder is missing. If you find one that has no effect on the way the car is running, then that is the suspect cylinder. Of course you will only want to remove the plug wires and reattach them while the key is off.

When you find the suspect cylinder, inspect the plug wire and the spark plug. If the plug is covered in fuel, you can be pretty sure the plug is not firing due to a bad plug or a bad wire. If the plug is very clean, you might be getting coolant into that cylinder from a bad head gasket. If the plug is dry, then the injector to that cylinder may not be injecting fuel into that cylinder.

If pulling plug wires one at a time appears to have no effect, then inspect all the vacuum lines carefully.

If you have access to a scan tool with a "datastream" mode, you might be able to narrow the suspect problem without having to pull wires, etc.

-Rod

[yotermanic]

Your problem could also be caused by a bad IAC solenoid. A quick way to check this is to crack the throttle plate open just a little. I use a nickle between the throttle linkage and the stop. If a little airflow helps, I'd just throw an IAC on it. Good luck with it!

[TomV]

Are you getting any engine codes? They come on with a lot of plug and wire related issues.

[denco]

You may have a loose vauum hose.
Listen for a hissing sound under the hood.
If you hear something, get a short piece of water hose(at least 1/2") and listen through one end while moving the other end to where you suspect the noise is comming from.

[robroy55]

Originally Posted by denco

You may have a loose vauum hose.
Listen for a hissing sound under the hood.
If you hear something, get a short piece of water hose(at least 1/2") and listen through one end while moving the other end to where you suspect the noise is comming from.

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My 2002 24 valve acted the same way. I had a new ignition coil installed and now it runs Great !!
Rob Roy