Back in May one of my cylinders went out. I replaced all spark plugs as they were at about 50K anyway... the problem appeared once more and then went away completely until now, except that now 2 cylinders went out.

I disconnected cables on the coils one at a time to find the bad coils, and then swapped them to different cylinders so I could be sure the problem was with the coils... and it seemed so, one bad coil in each cam.

Now I replaced both bad coils, I'm up to 5/6 cylinders working but the problem now is clearly not with the remaining coil because the malfunction stays on the same cylinder if I swap it. Could anything else be wrong with that cylinder, or is it just the fuel injector now? I suppose the spark plug is a possibility but it only has a few thousand miles on it. Just want to make sure I didnt miss anything.


Thanks!

 

Sounds like a injector to me..

 

Check the injector resistance. It should be about 10-14 ohms. Hopefully the bad one isn't in the back row (but how likely is this?). There is a connector by the power valve dashpot (passenger side of intake plenum). You'll have to find the pinouts on this site, I don't have them in front of me, but test the injector resistances. This seems to be a good way to tell. Also check your compression. It could be a bad valve in that cylinder, but the injector is more likely.

 

Just thinking about having to pull out the intake plenum again makes me shiver.

I read about on-car cleaning systems that attach to the fuel line and pass solvent through the injectors along with the fuel while the engine is running. Is it worth a shot?

 

1. those cleaning services are a short term fix if any fix at all
2. is it a front or rear injector?

 

its a rear. hate my life.

 

bah, pulling the plenum gives you a chance to pretty stuff up (paint/clean/whatever). no reason to disconnect the throttle body, maf or anything, if it's a stick, just reach down and unscrew the metal tube thing coming from the egr. unscrew all the holding bolts and pull the plenum off with the throttle body, egr valve connected. it is more of a pain than the vg i'll give you that. one less gasket to buy though. i got one for $7 same day from the dealership of all places.

 

I pulled the plenum about 6 weeks ago when I replaced the rear valve cover gasket. It was a decently massive undertaking, and that was when I had access to other cars so I could run out for tools/hoses, and a garage to do it in. Right now I'm at an apartment where I have no garage and am actually not allowed to work with the car in the parking lot.

I honestly dont know what I'm going to do, I have to drive the car on weekdays. Theres a place where I can work with it on weekends, so I might get a new injector, o-rings, yet another plenum gasket, and dive into it sometime soon... I just dont have the time though. And its not a stick.

 

Check the resistance across the injector and make sure it is the injector before you do the surgery.

 

speak of the devil... yesterday i started up my ve and was obvious it was misfiring. turned out to be the injector i just replaced a couple weeks ago (used). i figured since i had to pull the plenum i'd practice what i preached about cleaning up and painting. so i painted the aged as$ plenum and pulled the bad injector. the bottom o-ring was damaged so i'm assuming the injector might actually be good. either way i swapped all the good front ones to the back and installed a different used injector from the same rail in the front so hopefully if any go out, it'll be the used donor ones installed in the front. here's pics if anyone cares.

before


after (still a little cleaning up to do)

 

Yur brake fluid is dirty...

 

lol, man you nitpick a lot. hey i removed the spoiler to fix it at least. the car needs a buttload of work, cut me some slack

 

Hectic, you give me hope in a better tomorrow. A tomorrow in which my plenum shines, and the seat doesn’t vibrate due to the unbalanced torque of a V5 engine.

Nissan just sent me an invite for a free 100-point checkup, no strings attached. I'll let them measure the resistance and anything else they feel like testing. It will be funny because I'll come in with this rattling maxima, give them my list of what I know is wrong with the car and see if they can find anything I missed.

 

Okay today I went back to 4/6 for some reason. I dont know which one failed or why, but I ran 5/6 on a cold start and 4/6 on the return trip.

Could the ECU be a suspect? My last car was a Mits. Galant, and the ignition system was doing this type of weird stuff when the ECU fried.

In the mean time my dad suggested a novel way of possibly clearing injectors:

1. Remove all the junk attached to the throttle and run the engine (air filter, resonator, etc.).
2. Manually open the throttle to get the revs up, then shut its intake with your hand while keeping it open inside.
3. Just as the engine starts to choke as is about to shut off, remove the hand from the intake.

The spike of pressure change inside the cylinder is supposed to help clear things up.

 

if you don't know which one failed, how do you know you were actually running on 4 cylinders instead of 5? it's best to just figure out which cylinders are dead and replace the injectors. it's your most likely cause. you might want to replace the whole set for peace of mind. as far as the plenum is concerned, you should be looking to micheal for motivation there.. but if you're interested, i used some aluminum bbq high temp spray paint. looks very close to stock.

 

The power and vibration present at various RPM ranges changes a lot between 4 and 5.

 

it's more likely to be an injector than an ECU, I haven't heard of many going bad unless the heater core leaked on them

 

REPLACE THE O RINGS! i got in the car today and it took forever to start and the miss was back, i popped the hood hoping it was a front cylinder and luckilly it was. it was one of the used injectors, and another damaged lower o-ring. i ended up just swapping it with one from one of the original 2 faulty injectors (original o-rings are in much better shape). swapping the used ones from the rear to front paid off as i got the car back on all 6 within 15-20 minutes.

 

Just measured the 3 front injectors, bad news: 180 ohms, 50 ohms, and 490 ohms from left to right. I dont expect the rears to be much better, suddenly the prospect of investing in 6 injectors and waiting for something else to break doesnt sit so well with me... questioning the future of my Maxima ownership.

 

is your car in good shape besides the bad injectors? if so keep it. as is, your car is probably worth about $800 tops. even if you replace the injectors with new ones and still want you sell it, you can probably get around $2500-$3000. so you raise the value by about $2k just by investing in new injectors.

 

The only big thing besides injectors is the front suspension. Everything else is very good on the car, no rust or anything, tranny is great.

I was considering getting a low-mileage JDM VE for not much more than the 6 injectors would cost, but considering the work involved and the idea of another motor with its own issues, I will probably just try to replace the injectors.

 

yeah, just save what money you have for future maintenance rathre than risking some random motor swap problem that might arise