Ok, I need some help. Today, on my home from work I started to notice a slight power loss. It almost felt like as if you were to just bump the clutch and that was it. About 25 miles down the highway it started to get worse until there was hardly any power to pull the car, and my service engine light came on. This whole time the oil pressure was around 60ish maybe a little more, and coolant temp. was normal. I made it home, and checked the codes. Has active P0300 and P0301. The car also smelt like it was running rich (I think), the smell made my eyes water. There was also a light smoke coming from that vent on the cowl under the wipers, and it smelt like something electrical was burning. I checked the oil and it was right at the add line; which is not normal for my car. I have never had a problem with it until now.

Specs:
2004 Touring, with 125000 miles.
Oil has been changed every 3k miles with mobile1
Oil was changed 1500 miles ago
Spark plugs were done at 100K w/ platinum
Used to have top speed pro1 exhaust, but just went back to stock
Has aftermarket intake

Any help would be awesome. This makes my second car that is down right now, and I don't have a third. I have looked up the codes being #1 misfire, and multiple misfire. I wasn't really sure where to start (not too failure with gas cars).

 

Check the EC section of the service manual.

http://www.nicoclub.com/FSM/350Z/

It has troubleshooting procedures for those codes.

 

You are looking for the section entitled DTC P0300 - P0306 MULTIPLE MISFIRE, NO. 1 - 6 CYLINDER MISFIRE

Some of the info from the Service Manual is attached to give you an idea of the section and info that you're looking for.


If you are not comfortable with performing these steps yourself, I'd check with either a local shop that is a vendor on the forum, or the stealership for assistance.

You can also use the "Search" button on this website and do a search for "P0300" or "MULTIPLE MISFIRE" or "CYLINDER MISFIRE" to see what other folks have run into that have had the same code.

 

Thanks. I'll check into the service manual. And I will be doing the work myself. I'm a diesel tech, so I have everything available. I just wasn't too sure where to start with this one.

 

Cool. Good luck & come back to let us know what you found was causing the issue. I'd love to know and it may be helpful to someone else in the future if they find this post when searching.

 

Did you check to make sure your plug wires are intact and not the burning smell you described?

 

Good call on the plug wires.

 

It's a faulty fuel injector. Use search next time.

 

Alright so I ran an injector while it was skipping and #1&3 failed. Then I ran tHe test again while it was running fine and #1&3 passed. So, I'm leaning towards faulty coil packs. Today I'm gonna swap them around and see if the problem. Follows. And I dis do a search for my issue and there wasn't anything that helped. I forgot to add that the issue comes and goes. It will run fine then it will go to skipping then it will run fine. A friend of mine also said it sounded like a coil pack going out with the increase of heat. He also said that back awhile ago Nissan had problems with their coil packs and had a recall to replace all 6. But this was about 10 years ago.

 

There is no way that you can know 100% that is the problem in his case. It may be the most common item, but the best method is to test every possible cause and isolate the problem component (just like OP is doing).

If your post had said "That's usually a faulty fuel injector.", that's one thing.

Anyways. Thanks for your contribution.

 

So today when I got home. I ran the car, and right away it was skipping. Ran an injector test and #1 failed. Took the coil pack and rubber tube and swapped it with #2. Reran the test. #1 still failed. Removed the connector from #1 injector and ohmed out the injector. Had 14.5 ohms and I wanna say spec was 11-14, so I assume that injector is good. Took out #1 & #3 spak plug and swapped them. Retested engine. Started up and it was running fine. Ran injector test. All seemed ok. Teat drove about 3 miles and never messed up.... I don't know wtf is goIng on. Maybe bad cOnnection on injector?

 

Maybe connector on the injector or the injector itself. Intermittent problems are a PITA.

Since whatever it is appears intermittently, I would swap one thing and leave it that way, test multiple times until you get a failure. Document where you got the failure so that you can track what it follows.

Then change just one thing and leave it that way, test multiple times until you get a failure. Document where you got the failure for tracking purposes.

Once you have a good idea and you have it narrowed down, I'd get a known good part from the parts store (maybe an injector in this case), and swap it with one of the suspect parts. Leave it with that one change until you get a failure. If you don't, it's fixed.

If you do get another failure, swap one thing and leave it that way, test multiple times until you get a failure. Document... rinse and repeat.

Also, keep in mind that you could have multiple items that have problems. The easiest way to back yourself into a corner is to assume that only one part could have a problem.

 

How did the plug look?

 

Now you have the pros in here to help you out.

/me steps to the side.

 

The plug on #1 look like it was a little wet. Not wet with oil but fuel. It wasn't fouled out or anything like that. PhysiCal apperance was good. There was also some flakes of something on there. Kinda looked like rust flakes.

 

Swap the plug out (or all 6) for peace of mind. The ecu defaults and tosses in mucho fuel when it senses a misfire. Go through and clean the connectors with each coil pack, the maf sensor, and reinstall everything.

My guess is the plug is the issue, but the maf sensor could also be grimmed up. I am leaning towards the plug because the maf sensor would likely only cause the P0300 initially.

It's easy to go through and clean all that stuff as a base trouble shoot......primarily because it is quick and cheap. If the problem persists (assuming you have already replaced the coil with one you know to work)....I would move onto getting the injector flow rated, tested, etc.

Edit: Also, you might as well make sure you don't have a post maf leak (plenum, intake coupler, etc). The plenum bolts may have worked themselves loose on the front of the motor.....you never know.

 

Alright. Thanks you for the help. I'll clean the maf and replace the plugs then update.

 

My guess is coil pack

 

Was the coil blistered when you pulled and inspected it?

 

No there was no kind of discoloration or melting on the coil pak. But I also didn't pull that rubber boot from the actual coil pack. I didn't know u could do that until after I had already done it.