Nick Sion

Hey all.

I just purchased a 2004 350z 6mt. Previous owner had no idea what was wrong with the car, as it started up and did this:


After replacing all plugs and verifying I had spark, I am still left with this issue. I am for sure getting fuel. Upon startup, it will run like a boat, then if I attempt to get off the clutch into a gear it dies, same thing happens if I try to give it throttle in neutral. Only codes thrown are a misfire at the moment. The clutch master cyl also is out and the clutch is stuck to the floor. Unsure if this has anything to do with this problem.

The exhaust is currently off at the y-pipe while I wait on my single exit to get in. I have a 5at G35 coupe that I can source parts from, so I am really unsure as to what this could be. I have attempted an ECU reset, but oddly enough when I go through the process I cannot get the CEL to light up or blink... really strange. Any advice would be awesome!

Conway_160

iTrader: (1)

First thing first, you need to check for spark on all cylinders. If you have spark then you need to check for fuel. Air is kind of a given,

Do you have access to uprev or anything that can deactivate cylinders instead or having to pull coils?

jhc

Welcome.
I would focus on 2 things 1st. I wouldn't waste my time trying to get it to run correctly without the exhaust.
2nd this car may have been sitting for a long time, especially if the previous owner couldn't figure it out. Just bc gas is wet does not mean it's still good. I'd get rid of all the old gas and add only 1 gallon fresh 93.
At this point it runs but not well. Only change 1 variable at a time. It will either do nothing, get better or worse. If you change several things at once and it's better that's great. If it's worse you don't know which one to undo. Gl!

icer5160

iTrader: (4)

Start with the simple things and work your way up. If possible get a scanner hooked up and check for codes, OBDII scanners are insanely cheap now and a lot of auto-parts stores will scan codes for free! Don't simply guess. An engine running like that would almost certainly be throwing codes!

With the exhaust missing aft of the Y-Pipe, it's pretty hard to tell what sounds normal vs. abnormal. Sounds like it's miss-firing to me, but can't be sure from only inspecting over the interwebs while the exhaust is incomplete. Since you changed/checked the plugs, make sure you have your coils plugged up correctly. Very easy to get some of these crossed, the wiring harness coil plugs should be labeled (black text on white background) 1 through 6 for cylinders 1 - 6. As Jhc recommended, make sure you have good quality gas in the tank. Ethanol mixed fuel even if it's only 10% ethanol begins to separate pretty quick, even faster if you live in a hot, humid climate.
Good Luck!
-Icer

Painterguy39

IDK...but if that were mine,i would start looking for a new engine,sounds like a box of marbles!

Nick Sion

Thanks for the advice and the welcome guys! I've drained the gas and I get a consistent startup now with a slightly choppy idle. Still nothing when I give it gas, but while it runs for roughly 30 seconds I can ease the clutch out in a gear and roll it forward under its own power. I still have no RPMs on the dash and it will cut with throttle or after 30 seconds or so of idling. Any advice? Still no codes.

EDIT: Just replaced the crank pos sensor and no luck either. Same behaviour out of it.

icer5160

iTrader: (4)

Make sure all your cam and crank sensors are OEM. Aftermarket stuff for these Zs cause more problems. What do you mean by "no RPMs on the dash"? Are your gauges not working?

It sounds to me like your Z is in some kind of limp mode, most likely due to a major timing issue. Have you verified your coil packs are plugged in the correct order? Check your cam sensors and ensure they are all OEM. If the previous owner messed with the car, it's possible they replaced some of these with aftermarket units. I find it very hard to believe no codes are being thrown? How are you verifying this? Just because there's no CEL displayed in the gauge cluster, does not mean you don't have codes.
-Icer

epenbecks

check the maf. maybe.

Nick Sion

Thanks for the reply,

The crank sensor is OEM, I just bought it from Nissan and installed it. We have performed a few more tests and found that the car runs the same way with the throttle body off the car entirely, as in not plugged in and not on the plenum. As for the codes my scanner shows the following: p0183 (fuel temp sensor a high input) and p0462 (fuel level sensor a low input).

I checked all coil packs and It get spark on all of them, and they are in the correct order. I've noticed that if I ease into the throttle I can get it to idle as long as I want, but it runs really rich and really rough. As for the gauge cluster, I get no RPM reading, speed reading, or temperature reading. I also do not have a CEL/SES on and cannot get it to blink when performing the ECU/Idle air flow reset procedure.

Really stumped here, I highly doubt it is out of timing at this point, but any advice is always appreciated!

EDIT: I got the gauge cluster working, it turns out that the ac control unit was unplugged. I now have my SES light on.

Nick Sion

The MAF reads only .14 on my scanner, and when unplugged the engine will only run for maybe 10 seconds.

jhc

If you're in an area with mandatory 10% Ethanol 1st thing I'd do is get the injectors cleaned/replaced. It turns to gel over time.

calvin.w

Hey I know this is basic first step beginner kind of stuff but....
did you clean the MAF sensor and put new filters in?
If it runs the same without the throttle body (holy fack), then I think you may have a sensor issue. I tested my Z once, out of curiosity, by unplugging one of the MAF sensors (HR) and it ran rich and went ballistic. Try cleaning it and see what happens. Also check the wiring for any loose connections or damage. The best thing to do, like previously mentioned, is to start on the smaller fixes and work your way up until it's fixed.
As for your dash, just holy shat. That's ridiculous. You may have to check sensors or replace the whole cluster. The RPM, MPH/KmPH, and what- not doesn't work? Odds are you're missing a light behind that CEL icon. Rip it out and check on it. Also check the solders while you're in there.

The previous owner clearly didn't take care of the car. Either something major happened and random stuff actually went haywire, or they played around with random stuff and broke it.

Nick Sion

Thanks for the reply JHC, I'll take the injectors to my guys to have them cleaned first thing in the morning. I live in Texas and we do not require an ethanol blend, although again I am unsure what the previous owner did to this poor car gas wise. Will keep you posted.

Thanks for the reply Calvin. I ended up getting the gauge cluster to come back to life with all lights on. Turns out the AC control was unplugged (like what in the hell???) and that caused it to not operate as usual. I unplugged the MAF sensor just to test it out and it ran like an LS with a boost cam in it 😂. I'll take some MAF cleaner to it and see if I get a normal reading from it in the morning. Again, will keep you posted!

icer5160

iTrader: (4)

Hi Nick,

Recap:
1) Spark/Timing appear to be good.
2) Air intake/supply appear to be good.
3) Compression appears to be good (engine at least runs, albeit poorly), might still want to verify with test.
4) Fuel Delivery?

The two fuel system codes are interesting, after some reading on it it appears the A/C controls are tied in with the fuel pump sensor array. A lot of people experienced this issue when installing aftermarket radio headunits in their Zs. You should be able to clear these codes now that you have the A/C unit reconnected.

If you can, verify that fuel delivery isn't the issue. Rent a pressure test kit from a local auto store and check for solid pressure at the fuel rails (49-52 psi). Then I would begin checking the engine bay wiring for any obvious signs of tampering/splicing/damage. Can you confirm the throttle body is also OEM? Also, have you checked the IPDM (engine bay fuse/relay box)? Are there any signs of tampering or corrosion? Typically if there was any kind of engine sensor issue, you would be getting a code for it. Since no codes are being thrown for things like cam/crank/maf sensors, I suspect the issue is more fundamental/mechanical in nature (such as weak fuel pump, poor ground or damaged wiring). Getting your gauge cluster working again is huge, one more step in the right direction.
-Icer

Nick Sion

Thanks for the speedy reply as always Icer. I have finished up mostly with the interior, and now show a CEL. My code scanner does not in fact show any codes stored, and I have done the pedal dance reset procedure and that cleared nothing up. I got some new information from the previous owner. He had startup issues with the car and could only get it running if he started it in 2nd or 3rd gear. Sometimes the car would die out on him. He noticed this issue after installing a new clutch which makes me think that the engine was not at TDC and the flywheel was not aligned properly. Could be a factor in this mystery. Also, I have tested pressure at both fuel rails and I have a constant 45-49 PSI.

My good friend with a shop and Nissan diagnostic tool is able to see me in the morning, so I will have the car towed over there and we will run some tests in an environment that is much better for working on cars. Will let you know what we find.

icer5160

iTrader: (4)

Hi Nick,

This is a very important/key piece of information. The crank sensor at the bell housing uses magnetic markers on the perimeter of the flywheel to calculate the correct timing of the engine. If the previous owner made the mistake of miss-aligning the flywheel during the install, then the result is exactly what you are experiencing! TDC doesn't matter when installing a new flywheel, there is a small dowel pin on the back of the crank shaft that is used for the alignment. Most flywheel manufacturers machine them in such a way to be dummy proof (so you can't get the alignment messed up). However, there are some out there where it is possible to install the flywheel out of sync! Unfortunately the only way to know for certain if this is the root cause of your issue, is to drop the transmission and inspect the flywheel. It's also worth mentioning that even if the flywheel is properly clocked/synced with the crank, if the magnetic pick-ups around the perimeter have been damaged (from dropping, shipping, or mfg defect), you can also get results like this. Inspect the flywheel carefully for dings/dents/scratches around the perimeter.




Lastly, did the previous owner mention which brand/make/model of the flywheel and clutch he installed? Does he still have receipts? Long shot, but could be helpful information.
Good Luck!
-Icer

icer5160

iTrader: (4)

Hi Nick,

Any updates/progress on this?
-Icer

calvin.w

Same, I wanna know if he found something

Nick Sion

Hey guys!

Sorry for the wait. We pulled the fuel pump, disassembled it and found about an inch of dirt like material just below the filter. It turns out this car had some serious buildup in the gas tank that caused the fuel issues. There was still DIESEL in the tank (yes you read that right) even after siphoning out all the brown colored fuel. While there was fuel pressure when the pump primed, there was not enough flow to the rails and as a result it leaned out really bad. This partially explains the reason that even with the throttle body off the car continued to "idle" at 500 RPM.

After this discovery I was worried about what the heads and pistons would look like so we pulled the motor to disassemble it. After taking the heads off the motor we discovered that the pistons had maybe 2 inches or so of travel on the drivers side bank (passengers side where I did the compression test was fine), and when fully disassembled we found that ALL connecting rods on the drivers side bank had sheared and stretched horribly. Obviously we bought another DE and have since swapped it in. The clutch issue was not caused by the master cylinder, in fact two flywheel bolts had snapped off and warped the clutch disk so bad that the clutch would not disengage, and would often stick as a result. The car passed all electrical tests with my mechanics Nissan diagnostic tool which is GREAT! New clutch has been swapped in, new fuel pump, new motor, and we fire the car today to check and see if everything comes back to life!

Crossing my fingers and hoping for the best. Thanks for all the insight you guys provided, and I will update this thread with pictures of the damage and some videos shortly.

~Nick

calvin.w

I think my soul just died a little reading that. The previous owner really f*cked that Z up bad. When you said diesel, I started thinking "why tf would that even be a thing????" I'm guessing they went to a BP for the first time ever and looked at the green handles and thought "gReEn mEaNs dIeSeL." Oh BP....
Anyways, this story gave me cancer. Hope all works out brother!