kymera_gr7

Okay, so I've given up on the 0608 cylinder 1 misfire. I've done everything from check all my electrical connectors, replacing plugs, coilpacks, tested my injectors, knock sensor, MAF, CPS, everything I can think of. THE WORKS. This misfire just can't seem to be figured out. I'm beginning to think that getting a compression test to see if its a blown piston ring is even worth me dumping the money into to diagnose/fix.

Should I part it out/junk it, or endeavor to move on in trying to finally fix this issue before I move on to building on performance parts. Personally, after 3 months of frustration with this, I'm close to just putting my $1500 saved cash for the supercharger I was going to buy into just getting a 5.5 Gen for the 3.5L engine and go from there..

Trini Boom

iTrader: (5)

Out of curiosity, how did you test your harness, fuel injector, and coilpack?? I have not heard of someone giving up on a 4th gen because of a misfire which you apparently say you have troubleshooted everything and it is still there. Is the engine idling rough??

asand1

iTrader: (1)

Um.. rent a compression tester or pay $40.00 deposit (FREE). Do your test, if you have broken/worn rings or valve trouble get another motor for $300.00 or rebuild with 3.5 lower and cams, or do 3.5 swap. If compression is good, you are obviously overlooking something.

Have you swapped or replaced the offending coil/injector. Pull the rail and check spray pattern. Test coil for signal,spark, and resistance values?

knock sensor, MAF, CPS, are all a waste of time as they would affect ALL cylinders. Focus on #1 cyl. Compression, fuel and spark. Don't get distracted by by anything that doesn't pertain to just that one cylinder.

kymera_gr7

My father is an electrical engineer, he and I spent several hours with a multimeter looking for shorts and any fried wires/broken harnesses along the entire ignition and fuel system at EVERY point we could find using my Hayne's manual as a guide.

Injectors were pulled (all 6) and tested for resistance, all scored in the ~12 ohm range. Coilpacks have been fully replaced. And yeah the engine runs rough and just seems to be getting worse. The reason I believe it to be a blown piston ring is I have begun finding a fine coat of varnish with metal grounds in it around my #1 spark plug.



Spark is good, fuel is good as far as I know seeing as how my injectors are all fine and I just has the fuel rail cleaned. Like I said above I have gone over the entire ignition system trying to place what is causing this. Even took the spark plug back out and put it in the base of the coil to check for a spark against the engine block. I'll go rent the compression tester and see what happens. The misfire is very audible, sounds "hollow" I guess you could say, similar to a plunger being pressed flat against the floor.

Let's see where this goes..

njmaxseltd

iTrader: (19)

The fact that the injector passed a resistance test still doesn't mean it's actually spraying. Why did you spend all that time looking for shorts ect in the wiring harness?
All you needed to do was check for the signal at the injector and coil pack.
A simple plug in device which any mechanic should have, and you can probably rent at Autozone would take less then 5 minutes to verify the signals are present. From there you check the device both electronically and mechanically. A weak coil will throw a sprak over a plug's gap but will not fire it under load as a weak spark will get blown out under compression.

I think your father may have over engineered your problem. Think KISS.

Keep us informed.

queenz_97max

what color is your ride?? (in case you part it out)

kymera_gr7

pebble beige. :] though I will tell you this it needs a new clear coat, so if you're looking for doors or body parts, in good consciousness (also cuz with whats going on, I haven't been able to repair the front bumper or replace the hood), be warned that any panels or doors or anything like that, are going to need painted.

oh yeah interiour is the black "pleather" or fake leather. whatever you wanna call it. lol

kymera_gr7

The old man is a thorough and hard-headed hungarian/mongol, so I did it his way (love the guy to death though don't get me wrong) However he did say the same thing you did, just cuz it passed the electrical test doesn't prove its fine. However I did listen to them with an automotive stethoscope and they're all clicking and sound the same. Hmmmm.....

I doubt this is a coil issue. I've replaced all the coils and I just tried swapping them between cylinders to no avail, no change at all. @ my car lol

asand1

iTrader: (1)

Sounds like my dad, except he does step back and let me fix his **** now. Sounds like you ruled out the coil. Pull that rail and check pattern. Swap in a couple different JY injectors.

Do that compression test. Pull the fuel pump fuse and jam the throttle wide open. Make sure you have a battery charger going too.

kymera_gr7

Okay, well the car will be going in for its compression test friday. Til then I'ma fiddle with the fuel system and see what happens.

I'm still finding varnish (or maybe oil) mixed with a fine powdering of what appears to be aluminum filings. This is looking worse by the day >.<

Oh well, old man offered to help me do an engine swap. Lets see if I can push him into a 3.5 hehe... Will keep you guys informed on whatever happens.

cashoit

yo man, if the compression come back bad, jus do the swap and be done with it. All the money spent on tryin to fix misfire cd have bought replacement engine from outset.

I wd have replaced cyl 1 injector too. If that dont work then its something mechanical and yea replace engine.

U can try seafoam too

kymera_gr7

i seafoam the engine once every month or two. i could try again before the compression check but i doubt anything will change.

right about now i've already started pricing engines anyway. the old man said he may just forgo bothering with anything else and just do a swap. he even offered to let me go to a 3.5 (though that will be a little more difficult to supercharge >.< lol)

kymera_gr7

okay got the car from the shop. all cylinders were within spec according to the mechanic (readings around the 147psi range from what he told me) except #1. was reading a 104 there. So yeah, looks like im either doing the engine swap or going to have to bore the cylinders and do the rings. joy... lol

asand1

iTrader: (1)

Hone cylinders
new rings
new bearings
new gaskets
tensioner and guides
water pump
oil pump
valve job

Its called an overhaul and many times its all that's really needed. Tear it down for inspection and have it all miked by a machine shop first.

shiloh51933

iTrader: (5)

I'd just do the swap, sounds like U want the 3.5 anyway.

kymera_gr7

Thankfully my sister and her husband are machinists, very skilled ones at that. But for the overhaul it sounds like a little much for them. They're not mechanics haha. So yeah, shiloh is right. Its going to be a swap on the engine.

Now I gotta find out whats involved for a S/C'ed setup on the 3.5. If its far too involved, I'll just stick with a 3.0

sizzla

i hope u keep it, these r some damm good cars

ef9

iTrader: (8)

Good troubleshooting. I will need to check the compression of the Maxima I plan on purchasing next week.