MasterCookieman

So, was finally hoping to see my knock sensor today, stripped down everything to get the lower intake off, didn't realise what a nightmare it would be to get the timing belt cover off! Anyway, got everything freed up, all bolts removed, went to pull the intake up, and it was lose, I thought here we go finally...but something was stopping it. Turns out it's a PCV hard pipe at the rear that literally snakes in an around the back of the intake in a 'U' shape, over around the studs (green arrows). There's even a support bracket that attaches the PCV hard pipe to the water pipe above (orange circle)! As I'll be doing the coolant bypass, I think I can get rid of this pipe anyway? This PCV hard pipe could have gone straight over or around the EGR (which is removed), but no lets bend in and over the intake bolts...ahh why!! :angry: Anyway, I've looked at some images of the back of the engine (pipe highlighted with green arrows) - There seems to be two brackets (brown arrows), and I was able to remove the furthest left, but I can't tell if they're actually connected to the pipe. It could be simply held in pace my the PCV hoses (and that metal support bracket to the water pipe)? Basically the pipe has to be moved out of the way before the intake can be removed. I'd had enough for one day, so figured I'd post my progress and ask the experts. Any help would be very much appreciated. Cheers!

Looking for the right side (as you look at the engine) PCV hose, as I cut through mine... It's this one located here - Cheers!

Thanks for this, I would have replaced it with normal hose if you hadn't told me otherwise !

I thought the bit that screw into the plenum were the one way restrictor? Like this - http://www.ebay.com/itm/231706649069 Sent from my SM-G935F using Tapatalk

LOL, well guess that answers my question...and I now I know why they're connected to the plenum. So, a new piece of hose then... :oops:

Ok, I have my plenum off finally! I'm going to do the coolant bypass, the green lines is where I need to install the bypass pipe. The YouTube video ( ) which shows how to do the NA coolant bypass doesn't mention the pipes I've circled red. So I guess these have to remain. Unfortunately I've cut one of them. I'm guess if I simply remove these; coolant will be pumped out everywhere? Also, one of the main reasons I've removed the plenum was to replace the knock sensor. I understood I could get at it by just removing the plenum, as long as the EGR was removed, which it is. However, I see no way of getting to the knock sensor without removing the lower intake manifold, which I wanted to avoid as I don't want to mess with the timing belt (plus the extra work/time removing the intake). Any suggestions? Cheers!

ok, looks like there's a range of knock sensors...ranging from about £50 to £150, should I be buying a dealer part perhaps? Quite a difference in price...

I removed the EGR when I had the engine out. I was only 'playing' with the TPS to improve the idle, but I know it needs setting up correctly, but as I'll be pulling the plenum and cleaning out the IACV, I figured it didn't really matter at this stage. I think it was in a different thread I was told you get get to the knock sensor without removing the lower intake, if the EGR was vacant. Now that I'm seeing this image, it might just be possible! -

So, today I finally got around to inserting the 1M Ohm resister, and all was fine, still have a bit of an idle issue, but after playing with the TPS I actually had her idling at around 700rpm, at least temporally. when I pulled the codes I got good old 55! So clearly I have a dodgy knock sensor or harness. I'll be pulling off the plenum, changing that over, and someone mentioned that you can replace the knock sensor without removing the lower intake manifold. Can someone please tell me how easy is this? What I mean is am I going to waste half a day trying to remove the knock sensor with the lower intake in place, so may as well spend the time removing it anyway?

1M Ohm resister ordered! :)

Thanks for the advice, it all makes sense, didn't even consider I was using an incorrect resister - this is it - I'll get the correct resister and try again, but there definitely was an improvement in engine running, before it was a mess of spluttering, missing, stumbling, today it was actually smooth above 1000rpm. However, from what you're saying, if so many Zeds are running without a functioning knock sensor, I'm tempted to do that. Although I plan to replace the plenum and clean out the IACV, do the coolant bypass, and replace vacuum pipes with silicone tubing, so as I'm going that far...

Cheers, I pondered this, but didn't have time today, it made sense to eliminate the harness being the issue, but wanted to check here first too. :)

So I followed this - http://www.zhome.com/ZCMnL/PICS/detonationSensor/detonationSensor.html I tested the sensor side of the connector and my meter showed '1', which was the default display on my meter when selecting the ohm settings. There was no movement, nothing, as if I wasn't testing anything. Doing the same ECU side of the connector, I was getting 560 Ohm, which I believe is ok, what I should be getting. Then I stuck a 1k resistor in the ECU side of my connector, I started her up and lo and behold she ran far better, revved without stumbling or miss-firing, super smooth compared to before! However below 1000rpm wasn't good, without providing gas the engine finally would cut out, but I think this is a separate issue as I had been playing with the TPS a few weeks back, so I think the idle needs sorting but otherwise the knock sensor has obviously been at the route of the problem. The thing is using the resistor I'm still getting code 34! The resistor was only pushed into the connector, but had a good connection. Testing it with the meter the resistor actually shows 980 Ohm, not 1k, but would 20 Ohm make the ECU flag a code 34? If the wiring to the ECU was broken, then the resistor wouldn't have done anything, so everything suggests that my knock sensor (or its harness) is dodgy. So, I think I do need to replace my knock sensor, but not convinced it will clear my code.

An alternative is to get adapter mounting brackets to use a TT / aftermarket radiators. I also have an old NA radiator, would need checking over, but should be fine.

*EGR blanking plate. Sent from my SM-G935F using Tapatalk

No consult or anything, but something I considered. I remember reading somewhere to stay away from the Chinese leads on Ebay. It would be great if when I pull the plenum there's an obvious problem...like an EGR blanking playenthats not sealed...i don't have that kind of luck though! Sent from my SM-G935F using Tapatalk

I removed the EGR, but never had the engine running properly since. Holes are plugged in the plenum. It's good to know I can get to the EGR without removing the lower intake though. My time off has been reduced down to two days, as going to have to go into work now...perfect.. [emoji17] Sent from my SM-G935F using Tapatalk

Thanks everyone, after pondering it a while, thinking about everything I've done to date, I'm going to continue the battle for now. I have considered vinyl, so that is an option, but I'm going to concentrate on the running issue first. I'm going to pull the plenum, replace it, and whilst doing this I'm going to do the coolant bypass. I'll clean out the IACV and check that it's working. I'm going to replace the vacuum pipes with silicone ones. Thing is, if the knock sensor is causing the problem then really I need to replace it...of course there's the greater issue that the engine is actually knocking. I know you can place a resistor in the knock sensor wiring to fool the ECU, but what about if I just disconnect it? I'd really rather not pull out the lower intake manifold unless I have to.

So my paint job has again reacted as soon as it got hotter, again. Crazing/cracking...the only option is to strip to metal an try again, for which I no longer have facilities. That's not the issue though. As mentioned before I have a running problem, I've pulled codes 34 (knock sensor) and 12, MAF (but that should be because I had it disconnected). Even if there is a knock sensor issue, would this cause the engine to stumble and stall? The car runs great until I connect the confirmed 'good' MAF. So this suggests pump, injectors and coils are fine. Maybe an air leak then... The engine used to run fine 5 years ago, and so can't be a major issue, gunk maybe. Although history is limited, the engine should have only done 64,000 miles. In a nutshell, after 5 years I've had enough. Despite feeling a bond with the car I've rebuilt over the past 5 years, and not being the kind of person who gives up, I just feel that maybe I need to move on... If the paint looked like it did when I first painted (which was amazing!), then at least I'd know I had a great looking car after fixing the running problem....but I wont now. I have some time off work soon, and the plan was to pull off the plenum, replace with a clean shot blasted one, checking for any air leaks. I have the gaskets (except the IACV one). I was going to clean out the IACV, just seal it with gasket sealant. I have gaskets for the plenum and throttle bodies. Personally I don't believe there is an air leak. I did delete the EGR when the engine was out, but the plenum holes were sealed...it can't be that, but it's the only thing that's changed since the engine last ran. I just fear this is the end. I just can't do it anymore. Maybe there is a time to just give up, despite everything you've given. I need to move on....

Hey, So I'm looking for a Idle Air Control Valve (IACV) Gasket. I saw this - https://conceptzperformance.com/nissan-oem-aac-idle-air-control-valve-iacv-valve-gasket-nissan-300zx-90-96-z32-23785-40f00_p_2028.php I've taken a picture of the plenum and I know the shape of it, but I've seen variations, one with two sides (so two holes separated by a thin strip in the middle), another with one side blocked off (so no hole in one side of the gasket) and the final one which was just a general big hole (the link above). Can anyone tell me which one I need, and the cheapest place to buy one? Cheers!

Hey, yep all seems good, and after further digging it seems a good MAF voltage is 0.5v. I'm going to look for an air leak, hopefully tomorrow if there's time. Cheers

So, I have two MAFs, my original and a replacement I bought from Ebay some time ago. Without the MAF connected my car runs fine, hovering around 700RPM, but obviously doesn't rev past 2000rpm. Connect the MAF and there's spluttering, missing, stalling etc, but the car revs beyond 2000rpm, and can be driven - just not well. I tested both MAF voltages today - I got around 0.50v on both of them. It was a windy day, which didn't help, but nice to see the voltage climb with a strong gust. Am I correct that the voltage should be 0.80v? If so, does this mean they're both faulty? I connected my original MAF, car barely wanted to start...so I do think that one is dead; despite not being touched since it was last used and was working fine, bit odd that, it's all bit odd.

Hmm, I've looked at Vive, and after much deliberation decided that the Rift was the way to go. I realise that Vive has better movement tracking with 360 degrees as standard, but this can be achieved using Rift and an additional sensor, albeit experimental....but the costs keeps adding up. Personally I think that the Rift will win the battle in the end. I do have a PS3, if that's even supported anymore but if I'm honest I hadn't looked at PSVR, as it's PS specific and I don't consider it in the same league as Vive and Rift, plus as most of my gaming is PC gaming its pointless. You ask about the gaming side of things...well, ideally I'd like to login to Sword Art Online and live in it, lol, but I think we're a good decade away from that. I understand that games are limited at the moment, although I'd like play the games I've seen so far I can't help think they're not something I'd spend time 'professionally' playing....more of a laugh - like Wii bowling. In my normal game arena I would play driving simulations, MMOs and RPGs, but understand that we're not really there yet in terms of VR, but I accept that, I just want the experience. I think I'm just trying to justify the spend, but at the same time I want to support it. I think I'll love it, but don't want to have it for 3 months, then stick in in the corner cause there's no new content and no one developing for it....but I don't think that will happen. Saying that, people never really adopted 3D, and I played some excellent 3D games that just aren't as good in 2D. Really, I think I just needed to be born maybe 20 years later than I was. I remember when VR was meant to happen in the 90's and I was so excited about it, then I guess they realised it wasn't possible with the technology available at the time...and it just died off... so I'm maybe reliving that, and I finally want what was promised to me as a kid!!! :)

So, just wondered if anyone has an Oculus Rift? It's just reduced in price - so £600 with Touch and a game - https://www.oculus.com/rift/ I've watched plenty of videos on YouTube, read reviews etc. I'm almost sold. I have a PC that that according to the Steam Bench-marking App, will run it comfortably. I just wondered if anyone here had it, and can tell me their experience? More long term really, I don't want to use it for a month and be bored - I'd expect to be using it frequently, not like a fad type thing that you only get out when you have people around etc... It is the first piece of technology to get me excited in many years, and despite having plenty of home improvements to spend £600 on....I'm tempted to throw caution to the wind and just do it. There are demo days I could go to locally, but almost sure if I went along to one of these I'd buy the thing anyway!!! I have experienced VR at Alton Tower albeit a low res version, and thought it was great. I think I need it in my life!!! :)

So, the motors I ordered from China finally turned up today and I've spent the last 2 hours trying stuff....my Friday nights sure have hit a new time low. lol In a nutshell, they would have almost been a perfect replacement, they're exactly the same size. The extra shaft sticking out the back could be cut off...so no issue there, but the problem is the originals have splines cut into the shaft where the worm gear attaches, and this proved to be a problem, the new ones don't have splines. So, I tired using the new motor and attaching the worm with contact adhesive (all I had, other than plastic glue), soon as I powered the motor up it just spun the shaft inside the worm. Something stronger may have worked though. So I figured I'd use the shaft from the old motor. Although I finally got it apart, I destroyed the rear plastic bit that houses the brushes. To top it off, I couldn't get the old shaft out because of the splines!! So....I ended up attaching the rear brush housing from one of the new motors to the old motor. This worked, and everything seems ok. I'll try it on my Zed tomorrow. When I took the old motor apart, all seemed fine. I'm guessing it was the bushes causing the seizing issue. So, at least this provides options for those with dead folding motors.