My nissan xterra idles rough after its been sitting all day or overnight?

Question

The Xterra is a 2002 V6

Answer 1

Look for a small vacuum leak this will make the idle rough while the engine is cold! Try spraying carb-cleaner on vacuum hoses and around the intake gasket. You will hear an increase in engine idle if you spray where the vacuum leak is!

Answer 2

Does the vehicle idle normally after reaching operating temperature?

If so then your problem is moisture! Once car hot moisture disappears and wallah- no rough idle!

I would suspect that your spark plug wires need replacement!
Buy a good set($30 or less) and replace them like this:

Sort new wires by length and type(look at ends).

Take ONE wire off. Find its match. Put that new wire on car.
Common mistake is to remove ALL wires at once AND then you've turned an easy job into an extensive learning experience where you get to learn about firing order etc! Four, six, or eight(most likely numbers) will go to engine. Only one or two will go to coil(some sets include differing type coil wires so check old one's ends to select new wire).

Some models require wheel removal/engine removal to change so if thats the case replace the plugs at the same time(the hassle or labor fees will make it well worth it).

Good luck and let me know... I do care!

Answer 3

go out at night with water in a spraybottle, and with the engine idling, spritz water over the spark plug wires and look for sparks coming off of them....sometimes in humid areas, the evening moisture can effect the way the engine idles if there is a worn, cracked or scorched plug wire....it would just take replacing them to fix it

Answer 4

Not knowing what year it is,(this would be a big help) I will try and guess.

When was the last time you changed the spark plugs? If the plugs are fouled, then when you start it after it has been sitting, it will be harder to start and rough idle, until it heats up.

Try changing the spark plugs.

Answer 5

Do you see alot of black smoke coming out of the exhaust when it starts ? Sounds like it's loading up on fuel. Could be an injector or fuel pressure regulator leaking down while it sits for a period of time.

Answer 6

have your mechanic perform an injector cleaning service $80-90- injectors get a build up of varnish in them over time and need to be cleaned at some interval.

Answer 7

could be water in your fuel...go to your local parts store and pick up a bottle of water remover...just a couple of bucks..if that doesn't due the trick....start with simple maintenance items..plugs, wires, fuel filter...etc....