I just got my car back again friday for misfiring they supposedly fixed the problem for good this time (lies) it started misfiring again. I had took it in thursday and they supposedly fixed it as soon as i entered into the street it started misfiring again made a u turn went back in and got the car back friday.

Of course later that night it started misfiring again but it was on and off. Its the same coil blowing every time. I thought they had disconnected my cel because it didnt come on while misfiring but then it came on saturday and again the misfiring was not constant.

Yesterday i decided to do the gab mod with the stock holder i dremeled out the holes in the top and i drove around last night didnt notice anything Just a little louder. Today i get up to drive to work i forgot the gab was there until i got to the highway and my lowend was extremely strong and for some reason the car has stopped misfirng and the cel has turned off.

Why would the Gab mod cause this to happen? Not complaing just want to know the logic. Im thinking there might be something wrong with my exhaust from the y pipe back that might be restricitng exhaust flow.

 

I think that you should not mod until you have resolved all issues. This method eliminates variables and helps zero in on the problem.

 

This misfiring thing has been going on since january of last year and nissan has been the only one touching the car and the problem still hasnt been fixed every time is the last time. Only thing is a new engine or a new car. Dont know what else to do. Im hoping it may e my exhaust causing the problem.

 

had a misfire problem myself i change all my coils just to be on the safe side and slapped in some 350z fuel injectors and my problem went away but i had the misfire for like a month also changed my spark plugs

 

Do you have a 5th gen, or did you install those injectors in the 4th gen in your sig?

if those injectors went on your 4th gen I find that interesting since the Z 33 injectors are top feed. Did you modify the fuel rail to accommodate those injectors? How did you pull that one off?


So, to the OP, what are the codes?

 

All that has been changed by nissan except the fuel injectors and this has been going on since january of 07 every 1 to 3 months since then and the best they seem to do now is clean my grounds and they just this weekend they cut my grounds and regrounded saying it was shorting out the cylinder and i shouldnt have to comeback anymore. Ill be going back on thursday. The misfiring is practically under warranty.

 

So, what are the codes?

 

The cel light is not on now and i dont remember the codes of the top of my head but its the same coil thats blowing.

 

And lately its been misfiring with the cel off and thats without and before the gab mod

 

Check the plug, check the coil, check the injector of the misfiring cylinder.

 

How much would the injector replacement cost

 

Ive had the coils replaced about 6 or 7 times already and i have ngk plugs ive had the whole engine harness and my ecu replaced and nothing theres not many options left. Im working on rebuilding my exhaust since noticed that after i had my cat replaced that was falling apart with the test pipe and went to nissan and had the coil replaced the car stopped misfiring.

Until last month when my revolution speed sensor crapped out the day of the WPB meet and the car started misfiring again after the trans kept slipping and reving high. And that was longest I ever went without the car misfiring since it started I can also feel pressure building up in my exhaust which im sure is not good.

I think my y pipe may be clogged so im going to start there. Checking my coils and plugs is not really going to help me. I cleaned my maf and tb today because I needed to but car is still misfiring on and off. With the Gab i don't feel the pressure build up in the exhaust as much before i did it so im guessing its helping push the exhaust through.

 

put video clips on how its misfiring and all

 

yes buddy i have a 99 maxima with the 00vi and the 350Z fuel injectors are direct drop in plug and play no modication needed

 

I'm wondering if they actually did replace all that they stated that they did.

@ buddy.

BTW, you need an updated pic of your car, it's got that nasty USDMIM on it still

 

Yes they've done the work they said they did they know me and my car on first name basis and ive been in and out of the garage when they're working on my car +1 on the full tank of gas i get when i go though.

 

lol yea i know you know what im a go and tell me friend to make me another one

 

How do i take a video to show misfiring a video of the engine vibration?

 

Got a video camera / video phone etc...

And if possible, obtain the code the next it gets pulled, and report it on here.

 

Maybe you have plugged up precats, but how is it possible that its the same coil dude just tell them to replace all the coils and plugs, clean the maf, and throttle body. I think they got some tard working at that dealer. To check your precats smack them with a pipe or something to see if anything rattles inside. Also is this at a nissan dealership? Give a description of your car year? cali or fed spec? mods? mileage?

Dude for **** and giggles try running seafoam through your car, its five bucks just try and see if it works

 

yes i have a camera with video ill take a video of the engine when it starts misfiring.

 

when my CEL was on i didnt have a of coils but my car was misfiring like crazy couldnt even floor the car without it sounding like gun shots lol change all coils an injectors and the problem was solved

 

All coils and plugs have been replaced 3 times once by me and twice by them and then just the one that keeps popping. i cleaned the maf and tb today I was going to seafoam today but didnt get to it but I will try it.

They've been calling corporate for what to do next i told them about the my exhaust thought but not sure if they looked into it. Im going to try that before I take it back. Thankyou for the suggestions.

 

What was the total on your injector replacement. It doesnt soundlike gunshots if it's intermittent on and off which it is now the misfire goes away after 3k rpms. When its constant at 3k rpm the cel will flash. The cel will continue to flash until the exhaust passes. and i can feel the exhaust back pressure building up and being released the car speeds up and slows down. I had the same problem before I replaced my cat with a testpipe because my cat was completley gone falling apart and the exhaust smell was horrible and i still smell that smell if it isnt worse so something else is not right.

 

i paid $60 bucks for a set of used 350Z injectors with crazy low mileage from my boy vadim and he put them in for me and all

 

What exactly do you mean by you can feel the exhaust pressure building up and/or releasing? How exactly are you "feeling" it?

 

When you step on the gas if the exhaust isnt flowing correctly it is harder to push down on the gas and "my car slows down under pressure and when it is released the car picks up speed again and or flashing cel until the exhaust is released" and when the exhaust is flowing properly the gas is easier to push down on SMOOOTTHHH.

 

just get headers and eliminate the cats then you wont have any air restriction its prolly not your exhaust i never heard of things like that

 

Im thinking that because of the cat replace made the misfirng go away and the clogged feeling returned until i put gab in monday im thinking pressure is building up the cylinder and causing the coil to pop. Dont know what else to try but ill try the seafoam today. i already ordered a muffler and cat back parts just have to get the ypipe i dont know about headers it depends on the install amount i dont have a garage and ramps and things.

 

That sounds more like a carburetor problem to me...

 

What carburetor explain to me how the carburetor on a 2000 maxima works.

 

It's that round, black canister just inside the passenger side rear wheelwell, with all the different color hoses going in and out of it. Doesn't your car have one? Or has somebody removed it already? I think there may have been a factory recall on it at one time.

 

im noticing my misfire may be tied in to my exhaust flow exhaust from the feel of the car that where im heading since its been a little more that a year on this issue anything is an option except replacing the engine.

 

The throttle pedal never makes any physical contact whatsoever with the engine, so I'm not sure how you could feel any resistance.

 

Its a Pedal feeling of how easy it is to push the pedal down on acceleration and I can feel when the car slows down and it will pick up speed when the exhaust passes through. If it was happening u would be able to feel it thats best way I can explain it its an acceration feeling.

 

I can't get rid of my misfire code either (multiple cylinder misfire). I have replaced plugs and coils. Does your car burn oil?

Last week I changed my oil (was 2 quarts low!) and took my CAI filter off - was VERY dirty. Converted intake to short-ram and put a new cone filter on that my brother had laying around.

For some reason, the misfire was magically gone and the next day, my SES light turned off-- I was happy-***'d to say the least! The car has been running Great and smooth -- no more misfires. I even decided to take it to the track last night to see how she's running.. Guess what? On the way to the track, my SES light came back on! I havn't pulled the code yet, but expect it to be a misfire code again

Makes me wonder how I got the car to stop misfiring for a week -- did it have to do w/ my low oil, or was it the dirty filter/cai??

Please post if you find out the cause of your problem, I'm very frustrated and at a loss. I think next I may send my injectors in to get cleaned/flow tested. Any suggestions anybody?

 

The only codes I have are p0306 misfire on cylinder 6 they mave to check over the ecu and the engine harness wiring. Because its intermittent of an on until the coil finally blows.

 

 

Thanks NMex Max,

I pulled the code and sure enough, it came back -- was p0300 - multiple cylinder misfire.

I snooped around under the hood and heard a vaccuum leak. My brother and I thought it was coming from the intake manifold. We ran down to Courtesy and picked a new upper IM gasket. While IM was off, I checked the coils/plugs which I replaced a few months ago -- all still look good.
Put the new IM gasket on and put it back together -- vacuum leak still there!

Started playing around w/ the vaccuum lines going into the IM, and discovered where the leak was coming from. The cap, pictured below, had a loud vaccuum leak. Is this supposed to do that? I bought a cheap vaccuum cap from autozone and replaced it to get rid of the leak.

Picture is from greghome.com's maxima page, edited it and hosted on imageshack:



I guess my next direction is to check the o2 sensors and possibly get my fuel injectors cleaned/flowtested...

 

Well I did the seafoam and after a week and a half the misfirng has died down and hasnt misfired since the seafoam treatment im going to do it again this weekend for good measure.