jhc

You can use any vacuum line attached to the intake plenum. Pull the rubber hose off and connect the hose attached to your
Vacuum guage.

The reading should be very steady without huge jumps and drops, even on cold start/fast idle. Any auto store has these for very little money.

I used regular clear silicone, 3-4 mm bead.
Top of lower plenum. Apply silicone.
Place gasket, apply silicone. Repeat as necessary so each surface is treated.

Install all bolts and torque to 1/2, 3/4, then full torque. Let adhesive cure 1 hr and do your vacuum ck. Let us know how you solve your problem, sounds like a lot of moving parts.

dudegetalife

iTrader: (2)

So things just keep getting weirder and weirder on this car.

I disconnected the battery last night and just before taking apart the intake this morning i figure what the heck lets see if it starts up.

Started up perfectly ran great brought it out of the garage no issues.

Go down the street at low rpm it doesn't stabilize it goes from 500-1k at a stop sign.

Go down a service road and take it up to 60 and loud knock starts pull over and check the oil everything is good. Start driving again 40+ hear the knock. When I brake and go to a stop it stops.

Changed brake pads before putting it up for the winter so maybe a bolt is loose?

Get it back home into the garage at idle it sounds like its dying again its fully warmed up and not overheated at all.

I'm completely lost now.

jhc

I would get it running correctly, (checked vacuum?), then sort the brakes. 02.

KJFire4Life

iTrader: (6)

Have you done a compression check? It still sounds like a vacuum leak of some sort. Since you unplugged ECU then it sounds like possibly a computer reset helped the issue.....slightly, check all your plugs to the ECU. Maybe you bumped something taking the intake off. Does the steering wheel shake when you drove it? knock was consistently faster as you sped up? Might be something loose but a knock right after all this is suspicious. Hows your coolant look?

KJFire4Life

iTrader: (6)

The idle isn't right either and I can't remember if you said you'd done the relearn:
https://my350z.com/forum/maintenance...procedure.html
there is the link with 2nd post having instructions. Another thought just came to mind, did you happen to see if the check engine light was on? Check your camshaft position sensor connectors on the back of the heads behind the intakes. They are VERY prone to breaking that little set tab and mine was half unplugged a few months back throwing an engine light and running rough. Have you checked oil pressure also? if knock is under the hood that could be a culprit

dudegetalife

iTrader: (2)

Getting a guage later this afternoon to check. You said it should be in the 20's for it to be correct right?

dudegetalife

iTrader: (2)

Doing a vacuum check with a guage later this afternoon. Steering wheel was fine when I drove it and knock didn't increase or decrease in speed when driven just a knock every second or so.

Coolant is still the same green should need to be changed in 15k miles was last changed 20k or so ago.

jhc

My exp only is 22# on my 06 de.

KJFire4Life

iTrader: (6)

Definitely sounds like a vacuum leak or electrical then. I'm leaning towards electrical simply because it ran fine after battery was reset. Or it sat overnight and was working fine as it cooled down......as for the knock...maybe a tire low or brake part loose. no vibration in steering is good. Let us know what the vacuum numbers are!

dudegetalife

iTrader: (2)

My car hates me

Figured the vibration and noise was the lug nuts being a little loose 4 out of 5 were. Buddy came over with his vacuum guage and we unhooked the hose that goes to the intake on the passenger side and tested it ran #21 steady.

Engine light pops on.

p301

#1 cylinder that was the one that was loose and I pulled everything to make sure it was okay.

Pull coil and it disconnects from the boot. Try tugging on the boot with some pliers nope it disintegrates the top fml. Any tool to get out a boot from the bottom ?

p301 can mean spark plug coil or fuel injector based on what i read. since spark plug was good 12hrs ago with the car only being this morning i'll have to wait till i figure out how to get the boot off before I can pull it and check if its okay

KJFire4Life

iTrader: (6)

so vacuum looks great for idle. No problems there. #1 cylinder code.......hmmmm are you sure you tightened the plug in there? The coil could have been bad as well which would explain why a power loss might have made it run sem-decently for a little bit. Also would have explained a knocking noise if you were dragging a piston...........I would definitely check fuel pressure as well if a new coil/plug doesn't fix it! use a set of needle nose pliers and carefully twist and pull straight up! My moneys on a bad coil now......or a plug!

dudegetalife

iTrader: (2)

How do you use the fuel pressure testers that autozone/oreilly rent out? Never had the need to try to test it. Gonna have to buy some more needle nose pliers since I only have a 4" one.

KJFire4Life

iTrader: (6)

I can't vouch for the ones at advance or oreilly, but the one we have at shop is an inline fuel pressure gauge. You pop the connector off in-line i.e trace it back from rail to where a rubber or flex line connects to steel line. or at the fuel rail. I can't remember how the fuel lines are built on the Z's without going out to look at mine. I'll look at mine tonight and post up a pic of the connection point you can use. The ones from oreilly and such also probably arent inline, they just connect to the pressure side line and read pressure after you crank. Like a compression tester of sorts.

dudegetalife

iTrader: (2)

So he is an update and more confusion.

Installed new coil boot and plug today.

Start it up and clear code let it run for a bit and take it down the street.

Warms up and check engine light blinks then stops. Still pulls p301.

Rev it still doesn't get any code when sitting in place.

Drive down the street again halfway down blinks 6 times and then stops. Still pulls p301.

Possible that it has bad gas? I'm going to put in some seafoam but any other advice?

Why would it blink all of a sudden now. Doesn't that usually mean stop the engine will explode?

KJFire4Life

iTrader: (6)

Normally a blinking CEL is bad yes, but in the Z's case it indicates a misfire 9 times out of 10 that is catalyst damaging.........Is it misfiring still? Can you feel it while driving? I would start checking your wiring. possibly use a noid light to check coil plug connection. ECU might be going bad but I doubt it. Check and pull all your fuses to look at them physically. Don't trust a test light on this one. Also, did you look down inside the spark plug hole to inspect the piston head? I would also do a quick compression test on cylinder 1 to see what your numbers are like. Preferrably with all plugs out but you can do it with just 1 plug out. Just try not to start the engine with 1 plug out. I'm doing some research as well now. Also! Check you cylinder 1 injector!!!!!!! I'm starting to think this isn't an ignition problem. Could be a fuel delivery issue? Bad injector seal or bad injector

KJFire4Life

iTrader: (6)

Also it couldve gotten unplugged when you changed plugs by accident. Very easy to pop off or break those little plastic brittle clips

dudegetalife

iTrader: (2)

Checked all the fuses they are good, connector is still fully connected. Ran 3m fuel injector cleaner kit. How do I go about doing a compression test?

KJFire4Life

iTrader: (6)

Get a compression tester from loaner place. Advance, orielly, etc... will be a threaded in tube with a gauge that has a quick release on it. Pull spark plug, insert tube and screw it in, turn the engine over THREE times. Rinse wash repeat for all cylinders. This can tend to be a pain in the *** with the Z as you have to take the plenum off to get to some of the plugs. Just unplug ALL the coils and leave throttle body hooked up, spin engine THREE times each time and take the reading on the gauge and write it down according to what cylinder it is.