padilla03z

iTrader: (2)

Also I heard eBay coil packs make the other 5 go bad. Just go wit Nissan ones

myfirstzcar

How would a generic coil pack cause the other 5 to go bad? That's ridiculous. A random misfire is just that, random. One coil pack should bring up a misfire code for cylinder 1,2,3,4,5, or 6, not a random misfire code.
A vacuum leak can actually cause a computer controlled engine to go rich and idle low, since the ecu will compensate for the lean condition caused by the leak.....but that's only for smaller leaks. I really can't help you much more without having the car in front of me, or at least some more detailed info. Try having someone analyze your live data, maybe look at the misfire counter too.

padilla03z

iTrader: (2)

I don't know there is a thread about it or someone mentions it. Mayb its a rumor but just passing along what I heard. I know they rnt interconnected in that sense

BoostinJaxG

I was hoping to get a live reading on the misfire counts...but the 2 scan tools used to diagnose the misfire were unable to read them, i guess they were designed for other cars or something.

Since compression is good...that rules out any valve issues correct? and rings/pistons/cylinder walls should also be ruled out, right?

myfirstzcar

I would rule out the engine mechanicals and focus on fuel delivery. As far as ignition goes I'd say about the only possibility is a timing issue.
If the timing is advanced too much you can look at what the knock sensor is doing. If it's retarded too much it'll have no power.

I don't know much about utecs, but did you try resetting it to your original values? Is it still functioning at all? You do have larger injectors right? If your utec fails you'll have extra fuel at idle and not enough under boost. Maybe the stock ecu is trying to make it all work without the help of your utec?

BoostinJaxG

I dont know anything about the utec or how it works. I do have larger injectors...so i'm assuming the UTEC is what scales them, even at idle correct?

I honestly have no idea where the UTEC itself is installed...i've never looked for it. It must be somewhere behind the battery compartment or behind the glovebox inside. The theory that it failed is solid, i've considered it a few times myself...but it seems unlikely it would just crap out like that. It does seem though, if it did, it would show symptoms like this for the reasons you described i think.

I'm honestly leaning toward a vacuum/boost leak still...but i can't find it! I'm going to slap everything back together soon and if can't figure it out...i may just drive it to a shop around here somewhere. Maybe i need a smoke test, or atleast they can read the misfires live...

Xamaracer

*BUMP*

Did you end up finding the fix for this? I'm having a similar issue on my 04 350z

I am getting a multiple random misfire code, and I have the same exact turbo set up as your do (Turbonetics Single Turbo Kit). Although, what you are expereincing sounds much worse that what I am going through. Mine just runs like crap at low RPM's, but it purs like a kitten higher than 3k RPM's.

I have the following relevent mods:
Wabro GSS342 255Lph Fuel Pump
Deatschwerks 21S-05-0600-6 600cc Top Feed Fuel Injectors
TurboXS piggyback ECU tuned

I have changed out the spark plugs, nogo
Changed out all the coils, nogo
Fuel pressure at the rails are solid

Haven't checked for boost leaks yet, but when I changed out the plugs, they looked very lean, so i'm thinking it is a fuel delievery issue.

I was going to try changing out the fuel pump next with a Deatschwerks 300+ LPH intank, and after that have the injectors rebuilt.

Any and all suggestions are more than welcome here!

Silver_Z

any update have same issue ....same kit