Hi -

Last night, I got in my car and the engine was running really rough, check engine light flashing.

When I got home, pulled the codes, P0301 - cylinder 1 misfire.

Today:
Replaced the plugs, no change.
Replaced the coil pack for cylinder #1, no change.

I want to verify I got the correct cylinder based on the cylinder layout below.

Firewall
#1 #3 #5
#2 #4 #6
front of car

I also want to see if anyone else has any suggestions about what to check.

Thanks!

 

by what you said about changing coil pack and still no change,i would check the injector next. make sure its pluged in all the way and even unplug and see if there is a lot of corosion or some thing

 

also check coil connection and see if they are dirty. you might also want to check for any breaks or kinks in the wiring going to the coil pack, maybe even a slightly cracked part in the wire cover. good luck, I just went through coil pack issues myself.

 

I know this is gonna sound funny; but it worked when they told me to do it. I gave this advice in another post too! Take out the coil pack and spray some WD-40 directly on top of the plug (engine off) and into the whole at the bottom of the coil pack. Let it sit a little then turn on your car with the coil pack still off and let it run for a few seconds to get the excess liquid out. Shut off your car and put the coil pack back on. Turn on the car run in gently for a little bit and then check to see if the problem is gone. It might still have the misfire for about a mile or so. So just drive around for about 2 or 3 miles and see if you notice anything. That happened to my car and after I spent 500 bucks trying to fix it with parts an old friend of mine told me to try it. Sometimes the moisture will get in there somehow. And WD-40 removes water deposits. It truly worked for me! Let me know if it works!

 

Could also be a leaking IM gasket. Take carb cleaner and spray the mating surfaces. If there is a change in how the car idles, you got a leak.

S

 

cylinder layout is correct as you have it written.

check the fuel injector next. removing the upper intake manifold is not as bad as it may look. you should be able to complete the job in about 4 hours even if you've never done something like that before.

 

just because you got misfire cylinder #1 doesnt neccesarily mean cylinder # is misfiring. start the car and while your engine is running unplug each cylinder 1 at a time. if unpluging the coil doesnot change the idle that is your misfiring cylinder. just make sure cylinder 1 is really misfiring.

 

I had a similar issue where I was getting a cylinder 2 misfire but the problem was actually all the plugs and a damaged wire on injector 3 harness. Dont just concentrate on cylinder 1.

 

Check the injectors. I just had a cylinder 1 misfire. Got new plugs...no change, new coil...no change, new injector...my baby is back! I changed this today with the help of maximized98. Use an ohm meter to check the injectors. You cant reach them but there is a plug on the wiring harness located at the bottom left corner of the sideways "U" that the harness makes. This is the rear fuel injector connector. Should have 8 male leads...top row being 1-4 and bottom being 5-8. Put your meter leads on 1and 2 to test cylinder 1. Check cylinders 3 and 5 using the same method but from 1 to 5 and 1 to 6 on the fuel injector connector. I would do this test before you take the UIM off. If this is your problem...be sure to do other things while you got that UIM off.

 

excellent, detailed advice man.

OP: if you don't have a multimeter, grab one and get to work!

 

Thanks for all the help.

It turns out it was the #1 fuel injector.

I verified it was the #1 cylinder and that the coil pack and plug were good.

I removed the intake manifold and swapped the #1 injector with the #2 injector. Once I reassembled everything, the #2 cylinder wouldn't fire. This verified the the injector was bad. Bought and replaced the #2 injector (5 minutes) and everything was fine.

Thanks Again!

 

Hey guys I'm having the same issue with an 00 maxima..

It seems to come and go... Which makes me think it's not a bad coil or plug but more an injector?? I tried some injector cleaner.. seamed to help a bit, but it's still coming and going.. it's def damaging my cat cause I can smell it after a ride of it happening a lot..

Is there a how to on how to change youre spark plugs and injectors?

Thanks!

 

*facepalm*

Not to be an *** but...

You've been here for 9 years and you don't know how to read stickies or post in the right forum?

 

Sorry man didn't realize I ended up in the 4th gen forum

http://www.cardomain.com/ride/2076435/5

 

facepalm...

 

same motor....dnm