Occasional rough idle on warm start and P0304 code

[AZjeff]

2002 Xterra 150k with the 3.3 6 cylinder. P0304 is cylinder #4 misfire detected. Every once in a while on a hot start it will stumble and rough idle then It will clear up and run fine after 5-10 seconds. The Xterra has been used for the past year for short tripping around town and just sitting in the garage. Plugs,wires,cap etc were new when I bought the X and have only put 24k miles on it in 6 years. Maybe #4 injector is sticking open or shut? Seems to happen after it's been run and warmed up.

First thought is to run some injector cleaner through it and get it out and run it hard for a bit. Any thoughts on the best injector cleaner?

 

[Eddie]

"TECHRON FUEL SYSTEM CLEANER" is the best in my opinion. The fuel system version is stronger than the Injector cleaner version. Ed

 

[ocoilslick]

Have you checked #4 spark plug wire end? Might be the dreaded electrical white crud buildup. Might not be fuel related at all.

 

[bbhero]

You could have a bad wire...

Or a bad plug...

You'd be surprised but spark plug wires lose their jacket over time... And that can cause a rough idke condition....

I had that with a Nissan Sentra... I changed plugs, rotor, distributor cap... Better but not right... Changed wires... Voila... Problem solved... Car idled perfect.

If wires are 6 years old.... Change them.. . I bet that could be a issue here.

 

[AZjeff]

I'll pick up some Techron. Is there anything to be gained by running it stronger than recommended? Say put it in 1/2 tank instead of a full tank?

I pulled #4 wire and it looks brand new on both ends. Also never realized plug wires could age out and go bad with low mileage and garage kept.

This has happened 3 times in the past 6 weeks and only lasts for 10 seconds at most and always on a warm start. Does that sound like a wire?

It also always gets top tier gas.

 

[bbhero]

Wires in fact were my problem... With my Nissan Sentra and... My lady's Sunfire too.

No codes.... Just running rough at idle....

The Sentra experience was quite interesting... Having changed everything else... Rotor, distributor cap, spark plugs.... Not thinking it was the wires. Changed them as a last resort because if the rough idke continued... Obviously something fuel related going on. And... Wires corrected it one hundred percent.

In fact 2 and a half years later... Rough running cane back... I just changed the plug wires... Ran back to normal after that. Plugs only had 56k miles in them and they looked fantastic. I changed them at 75k miles...

The Pontiac Sunfire my lady had the same circumstance happen too.

Wires can and do go bad... On vehicles like that Sentra and Sunfire those wires are not like the ones on my 08 Nissan Altima VQ... Never changed the wires on it yet. At 326k miles on them.... Changed the plugs 2 times...

Wires for your Nissan should not be much more than $55... I know the ngk spark plug wires for the 98 Camry we have are $58....

Just a thought here AZ...


That may well be what's going in here... Maybe not. But 6 years... On those types of wires... May well be worth a shot. And the wires on the Sentra and Sunfire did not look or appear "bad".

 

[michaelluscher]

That 3.3 always had some kind of drivability problem
That NS60 distributor always loses the cam sensor, injectors fail at an alarming rate
TPS could be going or out of adjustment

I'd start cheap with standard tune up items (plugs/wires/Air & Fuel filters), clean the TB, clean the MAF, maybe dump a bottle of techron in the tank

If that doesn't do it, you'll probably be ohming out injectors or looking for vacuum leaks

I know my Villager starts rough if it hasn't been driven for a few weeks

Might be time to take it out for a longer drive now and then