Non-BMW - 2001 Nissan Altima Idle issues

[dude8383]

Maybe one of you guys could help me out here...

My parents were complaining about an idling issue on their 01 Altima.

After inspection I figured the alternator was dying, showed all of the symptoms. I was convinced that it was the alternator b/c a friend of mine had the same exact symptoms and replacement fixed it.

So I just changed the alternator and issue is still there. I used one of those bullshit code readers and I'm getting

P0304 & P0304 PD

I find it a bit hard to believe because wires, spark plugs and dist cap have less than 15k on them. I replaced them myself.

It sounds like there's a vacuum leak but can't find one for the life of me, I definitely took some years of my life from the amount of carb cleaner I sprayed to check for the leaks :(

I cleaned the TOB and I also cleaned the MAF...I don't know what else to do.

It seems to be a common problem on these Altima's but most guys say its the valve cover gasket that needs to be replaced. I don't see why I would to replace on this car since I couldn't find any leaks to begin with.

Any suggestions? Could it be knock sensors? TPS?

[monticello]

just because parts are new doesn't mean that they are good. i've gotten plenty of bad parts right out of the box. move your injector to one cylinder, spark plug to another, and wire to another. follow the misfire and it will tell you which component has failed. you'll probably find a dirty injector.

[gazellebeigem3]

just because parts are new doesn't mean that they are good. i've gotten plenty of bad parts right out of the box. move your injector to one cylinder, spark plug to another, and wire to another. follow the misfire and it will tell you which component has failed. you'll probably find a dirty injector.

yup. one at a time though. see what part the misfire follows.

[dude8383]

how difficult do you think these injectors are to replace?

[jflip2002]

Check the purge control valve (40961 part code), along with the carbon canister. When I worked for BMW/nissan, we'd sell one of those things a day. Also Cam/Crank sensors (23731 part code cam and crank same part number) go bad very frequently.

I obviously do not know what your problem is,but those are common cures for cars coming into the shop with an idle problem

[dude8383]

Check the purge control valve (40961 part code), along with the carbon canister. When I worked for BMW/nissan, we'd sell one of those things a day. Also Cam/Crank sensors (23731 part code cam and crank same part number) go bad very frequently.

I obviously do not know what your problem is,but those are common cures for cars coming into the shop with an idle problem

Something to look into nonetheless.

Thanks!

[SpecM]

did you check the output of the alternater before you replaced it?

does the car missfire under load (while driving)?

as for the VC gasket, it could be leaking oil into the plug tubes, causing a miss

[dude8383]

did you check the output of the alternater before you replaced it?

does the car missfire under load (while driving)?

as for the VC gasket, it could be leaking oil into the plug tubes, causing a miss

idle is the same if its in park, reverse, drive or neutral.

didn't check the output on the alternator b/c i was convinced that it was the issue.

i checked the plug tues and they're completely dry...i'm also going to check the spark plugs and make sure they look good.

[SpecM]

idle is the same if its in park, reverse, drive or neutral.

how about when you driving down the road? any misfires?

didn't check the output on the alternator b/c i was convinced that it was the issue

bad idea, no offense

[whterice]

those codes suggest cyl 4 misfire start there

[Rolla1990]

Did you remove and inspect the spark plug yet? You could have a leaking valve cover gasket leaking oil into the spark plug tube soaking the plug and wire.

If there's no problem, move your number 4 plug to cylinder 3 and move your number 4 injector to cylinder 2 and move your plug wire (or coil on plug) to cylinder 1. Then depending on which cylinder misfires, you'll know which component is causing the problem.

[jflip2002]

I called my buddy I used to work with.. he suggested a coil also. We used to sell a lot of those when I worked at the dealership also... not necessarily just for the Altima, but Nissan in general.

[SpecM]

an 01 Altima has the KA24, not the QR25, right?

if so, I wouldn't think its a coil, KA24s have one coil, and it it goes bad, you'd get a p0300 (random/multiple) or just a no-start

[dude8383]

KA24, dist cap :)

Yeh I know bad idea with not checking the alternator. You live and learn :)

I get home too late during the week because of school and work, so I will likely check the spark plugs on Friday.

There is no oil dripping into spark plug chambers.