I've never dealt with direct ignition systems before like the Maxima but I suspect mine is malfunctioning to a degree.

A couple of days ago, my car starts to miss like one spark plug isn't firing at all, and then there's this burning plastic smell that arises shortly after that. After several minutes of driving, the engine gradually seems to run smoother, but the smell doesn't go away. The next day, there was barely a noticeable miss, but easily detectable if I put the car in high gear at low speed and accelerated. The smell came back after some driving.

My thought was that the plastic smell is from a bad coil that's getting hot and burning the plastic casing or wire or circuitry in it and it's causing it to miss or be underpowered.

There's been a check engine light ever since I got the car several months ago that I've never been able to get rid of. The codes say there was a missfire, an IACV problem, and anot O2 sensor problem. I've replaced the O2 sensors and IACV and throttle body, but I still have a very high idle (1500 rpms usually). I think the codes may be related to this problem.

I haven't been able to find any threads addressing this issue on this forum so far so I figured I'd ask if anyone else has had a similar problem.

- Brian

 

Year / mileage?

Hopefully you didn't use el cheapo parts. For sensitive electronics, these cars only like OEM.

What cylinder is misfiring? Easy thing is to swap the ignition coil from there to another cylinder and see if the misfire moves. Even easier, just unplug the coil and listen for a change in the engine noise.

 

i'm assuming 00-01 if you're getting iacv codes (p0505). unfortunately iacv problems can short out your ecm, which i'm worried is your burning plastic smell. i am not sure if the misfire would be related or not, but the burning plastic and iacv code make me think that this would be a good place to start

https://maxima.org/forums/5th-genera...d-seconds.html

is the smell inside the cabin, or under the hood? if in the cabin i would pull the ecm and check for shorts. it is located on the floorboard below the radio, and is accessed from both the driver and passenger side.

this video should help your through this

 

Ecm - p0605.

 

Unfortunately (for you), I suspect Cornholio is right. Read the "New ecu ... " thread and especially, the "How to prevent ECU failures" doc in my signature below. It will save you a lot of digging and searching.
The bottom line: I think both your IACV and your ECU are bad. My document explains why, and the options you have to fix both.

 

I haven't been able to find any info regarding an IACV damaging an ECM either!

It's unheard of so my guess is your accelerator cable needs adjusting.

 

Well, then you haven't done your homework!
So, please do not confuse people by posting "advice" that is ignorant at best, and perhaps intentionally malicious.

 

 

says the guy who replaced his ecm because of it?

your problem is you refuse to listen to anyone's advice on here or believe anything you read from other owners and their experiences. By discrediting things that have actually happened to these cars for your made up conspiracy theories you are making it difficult for people who come to this site looking for help

 

maybe it was the Fuel pump seeing that 12 V at 10 amps runs into the the fuel tank with no terminal wraps. ?
So why wouldn't that short it out?

 

This is an absolute, complete and unchecked NONSENSE .....
To other .ORG members: Is there any way to shut this guy out? Are there any thread moderators still in place? If not, how do we re-institute them, or how do we install some other sanity measures?

 

He's a maxima TECH, though!

Yeah, but honestly, dude is a serial sh^tposter.

 

Dang, and I thought I was bad. At least I don't post stuff incorrect information knowingly. Giving falsified info that could potentially ruin someones car is a total douche move.

 

The wires coming from the ECM are approx. 18 AWG. each wire has an amp rating as to what it's capable of carrying Right?
15 amps isn't enough current to melt metal and plastic. It could warm it up but I doubt it would burn it.
It wouldn't generate enough heat.

 

Yeah, that guy's been a problem since he joined.
Anyone can make a mistake but he posts all sorts of foolish, dangerous and wasteful "advice" with zero real knowledge. Most of it's somewhat entertaining to people who have a clue about cars but a novice could really get into trouble if they stumble across one of his posts.
Just ignore anything he says.

 

Will do, thanks for the tip!

 

Thanks for the advice. I'll check out that article and watch the video. I was afraid that was the problem because someone mentioned it when I first started posting here. But at the time, I wasn't showing all of the symptoms, just one of them. When I smelled the burning, I was looking for other possibilities before settling on the ECM as the issue. But I'm convinced now.

I have a question. If the computer is the problem, if I take the car on a 10 hour trip, will I risk it becoming undrivable?

Thanks again.

 

For whoever asked, mine is a 2001 5sp with 160k. It was never taken care of before I got it a few months ago.

 

Does anyone know of a good Nissan mechanic in the Dallas area? I must have the car fixed before a trip on Wednesday, and figured a Nissan mechanic in the area might have one of the computers ready for install and know how to do the rest, too. I'm not great at soldering...haven't done it in probably 25 years. And I don't have time to order and wait for the part to arrive. In a tight spot...which usually costs me money. lol