Hey guys, looking for some help on this one. Have an 04' Z with 74k on her. Wound up with oil in the spark plug tubes so I did the vc swap.
All that went smooth until I started the car back up, and number four won't fire. Dug into it for about a day and a half. I have spark, and air. But no fuel.

Checked the injector and it seems fine. Jerry rigged a tester to check that it's getting power while the car is running. Fuel rail is not clogged.

Took it to an auto store hooked up a reader. Said it was something with the MAF

Ended up taking it to the dealer. The guy working on my car got pissed I did the vc myself. Whatever.

My thought is that it's the computer, something getting out of whack somehow when I was under the hood.
He however wants to dig around for something. I have a dealing the dealers dedicated "350z" guy has no clue what he's doing.


Any thoughts out there on a possibility?

 

what did the dealer say or did you not pay for diagnosis?

 

Dealer guy said he's "found a few issues that aren't related". Which he hasn't said what they are.

 

did you pay for that?

 

I haven't paid for anything yet. I told him and his manager both I wanted the cylinder misfire diagnosed and nothing else until they talked to me. I also told them I was almost certain it was an issue with the ecu needing re-flashed. Dude pretty much acted like he's gods gift to the Nissan Quest and I have no business telling him what I thought. Not to happy right now. Been five days since it went in.

 

not trying to be a dick, but......why would they tell you what is wrong if you didnt pay... and what makes you think something is wrong with the ecu? was running correctly before you did any work... yes or no

 

by chance did you swap cylinder #4 and #6 - they are logically laid out backwards ... the car will run like dog ****...

 

I told them to check it out and let me know what's wrong before anything else. That way I don't get hosed with a huge *** bill to replace something small. And most mechanics don't charge you up front. If you don't pay they can just keep your car.

Ecu is just the next logical place to look in my mind. Plugs, coil, injector, wiring, fuel rail, all good.
And yes. Car was running like a champ before.

 

See I thought maybe that had happened! Except that would cause misfire on two cylinders right? At any rate I went back in and checked it out by the book. Every thing is skippy back there. Even still I would guess that if that's what happened there would be fuel in the combustion chamber. It's bone dry.

 

why would they check it out for free? they have to pay their mechanics, and they cant do any work without authorization

if you want to throw parts at it guessing, by all means... waste your money, i almost guarantee it isnt the ecu. you will spend more than the diagnostic fee throwing parts on it that wont help... but hey, what do i know

 

I am paying. Just like if I had a tab at a bar. When I pick it up, I'll pay.

Money aside. I'm not throwing parts at it. I took it there so they could tell me what's wrong. I've had it happen in a truck before where the ECU faulted out when I replaced injectors. It just needed to be re-flashed. The ECU is where the injectors get the pulse timing. Just like there's relays that control your blinkers. So if something, for some reason, caused that to be knocked out of whack it could cause that. I'm just trying to determine a cause so I'm not blindly digging in the engine.

 

i will laugh when i can say, told ya so...

 

Well, I mean, laugh it up! You've told me me it isn't the computer. Oh and questioned how I'm getting it diagnosed. Thanks for the financial advice?

 

i am just saying if you paid the diagnostic fee, you would know exactly what is wrong with it.. you are still guessing

 

I have this exact problem right now. Cylinder 4 won't combust at all after doing valve cover gaskets and it's literally been 2 years of trouble shooting. What was your solution?

 

My issue ended up being the #4 and #6 coil packs being swapped. Like bealljk said, it’ll run like ****. And it makes absolutely no sense why they are laid out like they are. I’

 

Dude thanks for the reply on a 5 year old thread! Yeah I identified Nissan made it extremely ambiguous which connector goes to coil pack 4 and which goes to 6. I've swapped them back and forth and it misfires both ways but I get less misfire codes the way I have it connected currently. Right now it says cylinder 4 misfire only but it's a constant misfire. Was yours cylinder 4 misfire only also?


I pulled #4 spark plug out and connected it and wife turned the key and I can see it sparking, so that's why I figured it's getting no fuel or my compression is bad all of a sudden. I swapped the injectors last year but can't remember the result of that test. I'm compression testing it next weekend.

It ran fine before I changed the leaky valve cover gaskets so it's so a bit maddening. I haven't been able to drive the car in 2 years because of no free time with 2 toddlers but now that the youngest is 2 I'm managing to get occasional free time on certain weekends now.

 

I seem to have finally resolved my cylinder 4 constant misfire problem. I don't know exactly what did it, but I took the plenums apart again and undid the fuel injectors on that bank and unplugged replugged them a ton of times, put it back together and it works now. I can only assume that despite the #4 fuel injector being seemingly plugged in, somehow it wasn't getting a signal. 9.6v at all injector connectors so it wasn't the wiring.

 

UPDATE: I finally fixed the problem after 3 years. I couldn't find a picture or anything on the entire internet showing which connector goes to which coilpack on the drivers (US) bank. I originally had 2 and 4 swapped AND 4 and 6 swapped. I figured out at first the 2 & 4 were ambiguous and was focused on that but didn't realize on 6 that the rear most connector DIDN'T go to the rear most coil pack. I read what you said above but thought that the front most cylinder was 6 (it's actually 2) so I thought what you were saying was what I'd already figured out. Wow.

July 2022 this guy made a video of this exact problem, and also said he scoured the entire internet and couldn't find a diagram of which plugs into which coil pack. All other cars I've worked on the coil pack connectors plug-in in sequential order. I could've never dreamed Nissan would make it this way and that there'd be no info anywhere about it.

 

A four-cylinder engine can work on just two cylinders. Thus I don't believe a single coil is an issue, as for coils from scrooz.com.au. Your no-start issue is most likely unconnected to your leaking spark plug wells. Some engines can generate a large suction leak from oil spills. Still, I don't believe Honda/ Acura automobiles are engineered this way. Begin with the fundamentals. Spray a can of carburetor/intake cleaner into the intake and try to start the automobile. If it tries to start, you have a gasoline delivery problem. Next, look for a spark. You don't need a spark tester; remove the coil and plug.