Solutions for a rough idle?

[Acclaimed]

I just purchased a used 01 zx3 from ebay. Carfax checks out ok but it needs some tuning.

At idle it bounces you a little bit. The exhaust sounds like a drum beat instead of a steady hum. It doesn't sound like its about to choke out though. The engine shudders as I rev it also. It reminds me of a go-kart engine as you give it gas. I just changed the valve cover gasket and noticed the sparkplug slots are pretty dirty with a cruddy/chalky white substance.

What are the first few things to check for a rough idle? Plugs, wires, timing?

[Sponsor]

[venomfocus]

check plugs first. wires can last for a long time without problems

[killer ZETEC]

also check the wires that fire the coil pack, that little plug can cause a lot of issues, mainly due to the wires getting pinched right there and shorting to ground on the bracket or jsut breaking offf like mine did. btw do you get a cel?

[Acclaimed]

Originally Posted by killer ZETEC

. btw do you get a cel?

Little help on what you are asking on that one?

[Kfokus]

cel=check engine light
tps =throttle postion sensor may be bad, causing rough idle.
Unplug it(its right on throttle body) if it runs better w/o being plugged in you found the problem.
Also clean the mass air flow sensor.
This is located right after air filter box.
Buy some maf cleaner(spray bottle @ ur local parts store)After you take off intake, or just the maf tube.
Spray down the maf sensor until liquid coming out on other side is clear.
then reinstall and start car to see if it helped.
And a new airfilter can help alot if yours is really bad.
Its a good idea to go ahead and atleast buy a K+N panel filter.which is same size as stock paper filter. Only its reusable.

[silveib]

some one correct me if i am wrong but if you get a white chalky substance on your spark plugs doesnt that mean that you are leaking coolant into the combustion chamber? i only know because my coolany dropped a little over the few years ive owned my car and my mechanic friend checked the spark plugs for a white substance to make sure it wasnt leaking into the motor

[killer ZETEC]

well they might have been in the engine too long.. but as for coolant it really doesnt say about colors on the plugs. but if your car smells like coolant when its running and the exhaust basicly makes you gag then coolant is burning somewhere,lol. as for the white stiff the head on the car is aluminum if water from the road gets in there it will corrode slightly, its nothing to wirry about jsut dry the holes out and put new plugs in when you get a tune up.