My 92 maxima se with 215000 miles one it has been idling very roughly lately. When i start it, it will run fine for about 10 seconds, then the rpms will drop down to around 400 then go back up. This is when it is in park. In In any gear besides P or N the rpms will drop and the car shuts off. Also when im driving, it will get up to about 2k rpms, and drop down to 1.5k, then go back up. It feels like someone is hitting the gas, and then the brake, and it wont go any faster. When i stomp on it, it will get up to 4-5.5k and either do the same thing or just shut off. It feels like the tranny is slipping, but that wouldnt explain the shutoffs. I really need ur opinions of what could be wrong. Thanks ahead of time. Ill try to get a pic of my car in the future also.

Sounds like it might be a vacuum leak. I'd double check your hoses and make sure there are no leaks.

Good ways to find a leak would be to use a spray like keyboard cleaner. If you spray near the potential leak the engine will bog due to the carbon dioxide.

If you happen to smoke you can pull off a smoke, take a puff of smoke, then blow it into the intake. If there's a leak you'll see smoke coming out of it in no time. Kind of weird, but I found that it worked pretty good for me while I smoked.

thx ill try it and get back to ya

92maxpwer wrote:My 92 maxima se with 215000 miles one it has been idling very roughly lately. When i start it, it will run fine for about 10 seconds, then the rpms will drop down to around 400 then go back up. This is when it is in park. In In any gear besides P or N the rpms will drop and the car shuts off. Also when im driving, it will get up to about 2k rpms, and drop down to 1.5k, then go back up. It feels like someone is hitting the gas, and then the brake, and it wont go any faster. When i stomp on it, it will get up to 4-5.5k and either do the same thing or just shut off. It feels like the tranny is slipping, but that wouldnt explain the shutoffs. I really need ur opinions of what could be wrong. Thanks ahead of time. Ill try to get a pic of my car in the future also.

You might have one or more problem, but it sounds like one or more of your coil packs are faulty, which is causing the stalling/shutoff. Usually when they start going bad, they will test out fine, but fail under load.

The coil pack(s) could also cause the idle fluctuation, or it could be a dirty throttle body or dirty IACV (idle air control valve), or Mark could have hit upon it with a vacuum leak.

When my car idled rough, I had a front coil pack that was cracked. It was clearly visible when you pulled it. When my car had the stalling problem, it turned out to be one of the rear ones -- it looked perfect and tested out OK. I bought a new (used from a strong running car) rear coil pack and pulled them one-by-one to determine which one was causing the problem.

Ahh, yeah. I forgot about the coil packs.