streetzlegend

iTrader: (2)

Should be the same, 3.5 maximas have same coils.

streetzlegend

iTrader: (2)

How small of a gap would it be ok to use? .020 perhaps?

Chris@FsP

iTrader: (4)

I've never needed to gap any plug closer than .28- .30. I'm not really sure what your issue is. How do the plugs look, and what heat range are you running now? Is it always the same 1 or 2 cylinders that miss, or is it all over the place?

streetzlegend

iTrader: (2)

They are one step colder, ngk v-power. When it misses, it is just a single hicup, its not like it suddenly starts to miss nontop, it just a single pop (like if you hit a limiter really quick). I have no way of telling which is the cylinder that is missing, the plugs all look the same and look normal, nothing out of the norm, a little black on the base, but no specs on the ceramic, melting or anything.

streetzlegend

iTrader: (2)

I just did two runs back to back, one with more timing, and one with less timing, with less timing it missed like crazy, when I added more timing it was very smooth, only missed once. Im going to richen up the mixture and keep it with more timing.

MardiGrasMax

iTrader: (8)

Its about voltage to the coils. The OE wireing is old im sure. A Boost-A Spark is the answer.

streetzlegend

iTrader: (2)

Yeah it might just be, it is a 1997. However I advanced the timing more and richend the AFR to high 10s uptop. the car barely misses now, only at high 4k once and thats it, it cleared up alot! Feels awesome. I am still going to invest in some kind of voltage booster. This friday im going to the 1/8th track with nitrous and slicks, I am expecting 7.8, hopefully.

HotRodG35

iTrader: (7)

I haven't read every post but have you done a compression test ? I had similiar problems and ended being low compression due to cracked rings.

streetzlegend

iTrader: (2)

I am pretty sure thats not the case, the missing is almost gone now. It's in the tune or ignition. I will still check compression eventually to make sure the engine is doing good, but there is no reason I should have cracked rings.

SmallTuner

iTrader: (2)

timing should be around 17-18 degrees

binder

iTrader: (8)

so advancing the timing helped??

i have this on occassion with my street tuning. It's usually around 4500 rpm or so and it's one "pop" like u said. No knock detected. It does it at 13psi on my build block and about 14* timing. At the 4500 rpm i'm nearing the 13psi but the timing is more around 11*.

coils are all good, plugs look good and i changed them to knew just to be sure and set the gap to .026. It only happens on occassion so it's weird. I'll go weeks without an issue then it'll happen.

streetzlegend

iTrader: (2)

Yesterday the night was cool, went for a drive and was missing a little still.

Yeah same here, its a bit annoying man. On my J&S I cant adjust timing exactly how I want, you can only retard X amount per PSI. So since my stock ECU has a big dip in timing (down to 14 @ 4k), when I retard, it drops my timing below that 14 maybe down to 10's. But if I retard less timing, then I will end up with timing being too advance at higher rpm's and the J&S starts lighting up telling me there is knock retard happening. Hopefully soon ill get my EU to hook up to the JS so I can remove that dip. I have been fighting with this since for I hooked up the JS, so I am 70% sure its timing related, being too low.

Either way, I ordered a voltage booster, maybe that would help.

binder

iTrader: (8)

cool

ya, when my intake temps go up my haltech pulls a good amount of timing and it seems kinda low to me at times so i was thinking misfire due to low timing since at those points i'm low timing with no knock so it can't be detonation.

When it happens to me i get quick drop of timing down to usually 0*, drops about 50rpm then resumes back to normal asap. email me at jeffbinder@gmail.com and i'll see if i can get a clip of my log to show you what it looks like.

streetzlegend

iTrader: (2)

Perhaps it actually is detonation, from EGT's being so high due to the very low timing. My log shows the same thing as yous, during the misfire it shows a spike in timing to 0 then back to where it was, also maf voltage used to spike up to 5v then back down (dont have maf anymore).

Yesterday I was doing some reading and asking around on the maxima forum and found some very old posts (from MardiGrasMax) showing how JWT did their timing on FI vq30 ecu's. They actually put 10 degree's of timing across the rpm range!! very crappy tune (lazy asses), so that make me wonder, maybe this issue is not really because of timing, but weak ignition. Once I get the voltage booster, I will def find out and let you know.

streetzlegend

iTrader: (2)

So after doing everything I can think of, its still missing, brought boost down to 10-11, running about 15-19deg, no meth, AFR at high 10 (10.8-11.0) and its still missing.

Also had a bad alternator, so I was praying that was the issue for the misfire, put in another duralast autozone alty and nothing still missing (maybe I just need a real nissan alternator, or a high output one).

A buddy of mine suggested to put heatshrink or tape on the coil packs to better insulate and prevent them from shorting out, has this ever been an issue?

westpak

iTrader: (19)

I have had terrible luck with Autozone alternators on other cars

streetzlegend

iTrader: (2)

Yeah, last week I went to exchange the bad one, I told them to test the one they were giving me and that one failed too on their bench. Went to another store to get one that actually would pass their test. I just dont know if to get a nissan/hitachi alternator, or get a high output one. A quality high output unit goes for $300, nissan one goes for $200. both 1yr warranty.

MardiGrasMax

iTrader: (8)

AFR at high 10 (10.8-11.0) Thats a tad rich IMHO, try to get it up in the mid-high 11's, at 10psi that should be okay.

streetzlegend

iTrader: (2)

Yeah I wanted to try that and see if it clears up. on the 3.0 mid 10's for 2-3 years was perfect even on meth, never missed. Maybe on lower compression it makes a difference, having a leaner tune. Once I bring it back up to high teens like 17-18psi, is mid 11's without meth and safe conservative timing still good? or get closer to 10s?

binder

iTrader: (8)

rich can cause misfires.


and the coil packs are on the plugs so how are you supposed to shrink wrap them is the first question and second question is what magical properties does your buddy thing shrink wrap does?

It won't help. If you think it's a bad coil pack then replace them. Usually when one goes bad it just goes completely and doesn't miss on occassion or at certain boost levels. It's all the time.