Removing the upper intake manifold on a late 1992 Q45 to replace injectors

[Kierco]

Although I am a Mechanical Engineer and quite familiar with the wrench, I have never attempted anything like this before. Can anyone offer a blow by blow around the tricky areas? Also I have had no real luck identifying the proper color code for the replacement injectors. I removed one injector that was not inhibited by the manifold but found only part numbers. I have written them down if that helps. Vin search "no help" etc. Some suggest just replacing them with no color code injs.

[Q45tech]

The proper way to replace all injectors is to totally remove the entire fuel rail and do the injectors and o rings and fuel hoses on a work bench.

Instead of bending over the exposed engine.

If you pull an injector without draining the fuel rail - the engine fuel will fill up a cylinder and hydrolock the engine!!!!!!!!!!!!!!!!!!!!!!!!!on the next attempted start.

[PopPop]

Always try to twist or turn any hoses prior to removal to break the seal. If U have had Plenum off before they are easier to remove but, if it hasn't been removed in years then U may have to cut a hose or two. Just take your time and the hardest will be at the back area around heater core hose area. Move the cruise control and accelerator cables out of your way and I like to remove my Throttle body to clean off the backside. Check your EGR and IAC system for carbon buildup. Have 8 plenum gaskets and TB gasket, IAC Gasket, EGR Gasket, coolant temp. sensor, PVC Valve, hoses, TB Cleaner(Valvoline Syn-tech), Di-Electric Grease. U can wait until U remove plenum to see what all U may need. Always stuff rags in your intakes to be safe!

[96Qowner]

Here's Wes's plenum removal writeup from Q45.org:

http://www.q45.org/plenum.html

[ScottJackson]

Watch out for the VVT hydrostatic rod! It's under high tension and the spring will shoot it straight through your head as you're bending over and lifting up the intake! It won't kill you, but will likey disfigure your face/skull and adversely affect your psychological well-being (like Phineas Gage)... J/K :p

[elwesso]

Watch out for the VVT hydrostatic rod! It's under high tension and the spring will shoot it straight through your head as you're bending over and lifting up the intake! It won't kill you, but will likey disfigure your face/skull and adversely affect your psychological well-being (like Phineas Gage)... J/K :p

how do you have to mess with that thing to take the plenum off?

[maxnix]

Watch out for the VVT hydrostatic rod!

Care to highlight that in the picture? I would like to know where this potential killer lurks.

[ScottJackson]

It's deep down inside the motor... most of the time. However, if it hears you bangin' around on the plenum it will come and strike. Usually it's just down chatting with the chain guides, plotting. Sometimes though... just sometimes, it has a visit with fuel injectors or the knock sensors. Those are the times when you're most likely to feel its dreaded wrath. You can't ever tell exactly where it is when you do your plenum job as it's invisible, you just have to be lucky and hope. That's the reason there's no grille on the early Q's. The engineers at nissan (who were from an evil parallel universe, as if we couldn't tell by the VH's nasty inherent attitude already) thought the VVT rod might try to exit through any percieved opening and therefore couldn't put a grille on the Q. The belt buckle was a symbol, more than anything, as a reminder that this VVT rod should be kept closed... TIGHTLY. It was later found that the upper plenum did a sufficient job of containing the invisible monster, so the grille was introduced. However, just because there may be a grille on your Q, doesn't mean there's no VVT hydrostatic rod waiting to mess you up when that plenum comes free. About the safest way to tame the beast for enough time to do a plenum job, is to get into the upper rpm's a bunch before you start wrenching. The rod will get tired from advancing the intake cam so much and will be less likely to strike. I mean, after all, this is a functional thing and not just some useless killer that was put in the Q for no reason. I don't know if it would go after a grizzly bear, but I don't think many grizzly bears would be able to navigate around all those little hoses by the throttle body or be able to pull up all those little 10mm head bolts that clamp the plenum down.

[elwesso]

It's deep down inside the motor... most of the time. However, if it hears you bangin' around on the plenum it will come and strike. Usually it's just down chatting with the chain guides, plotting. Sometimes though... just sometimes, it has a visit with fuel injectors or the knock sensors. Those are the times when you're most likely to feel its dreaded wrath. You can't ever tell exactly where it is when you do your plenum job as it's invisible, you just have to be lucky and hope. That's the reason there's no grille on the early Q's. The engineers at nissan (who were from an evil parallel universe, as if we couldn't tell by the VH's nasty inherent attitude already) thought the VVT rod might try to exit through any percieved opening and therefore couldn't put a grille on the Q. The belt buckle was a symbol, more than anything, as a reminder that this VVT rod should be kept closed... TIGHTLY. It was later found that the upper plenum did a sufficient job of containing the invisible monster, so the grille was introduced. However, just because there may be a grille on your Q, doesn't mean there's no VVT hydrostatic rod waiting to mess you up when that plenum comes free. About the safest way to tame the beast for enough time to do a plenum job, is to get into the upper rpm's a bunch before you start wrenching. The rod will get tired from advancing the intake cam so much and will be less likely to strike. I mean, after all, this is a functional thing and not just some useless killer that was put in the Q for no reason. I don't know if it would go after a grizzly bear, but I don't think many grizzly bears would be able to navigate around all those little hoses by the throttle body or be able to pull up all those little 10mm head bolts that clamp the plenum down.

This post brought to you by WACKY TOBACKY...

[pito11213]

LOL.

Well I did the injector removal and damn was that a pain. Wes helped me alot over the phone even though it was damn early for him (thanks Wes)

The hardest part had to be the EGR valve in the back. You would be shocked to know the prices of these hoses when purchased individually so please just by the kit. It will seem expensive but I spent almost $300 just for 6 hoses, thermostat and a bottle of BG. Disgusting how expensive those hoses seem.

I dont know what high boy is talking about as far as something smashing you in the face but it is pretty difficult like everyone said, if the plenum has not been removed. Not something you wanna have to do again within a short time.

[maxnix]

Not something you wanna have to do again within a short time.

Why the wise ones do everything the first (and hopefully only) time.

Reminds me I need to ohm my injectors.

[superuber]

how do you have to mess with that thing to take the plenum off?

Care to highlight that in the picture? I would like to know where this potential killer lurks.

Got'em! Hook, line, and sinker!Hey Scott, whats the routine maintenance on the kanutter valve?

[breaksr]

The best thing to do is to not break those breather hoses since they are a fortune. Make sure you replace all the rubber fuel lines conected to the fuel rails since they are probably dried and cracked. Just buy about ten feet or so from Scotsdale and cut up what you need. Remove the throttle body, disconnect the EGR, pull all the obvious visible hoses. Now there are a couple of hoses that are under the plenum that are a little tricky. Unbolt the IAC on the back of the plenum and you will see there is an additional hose that is tricky to get to. You need all of the 10mm sockets and open ends you can find to turn various clamps and bolts. There is a 10mm bolt that holds that pipe that sticks out underneath the throttle body that is a major pain to turn. Once you have the plenum off let it soak in various solvents to remove all the carbon inside of it especially where the EGR hooks up (mine was totally plugged). Scot stop sniffing that liquid wrench.

[Q45tech]

If you have the engine long enough and live in a warmer climate you will be replacing ALL the $400 worth of hoses more than ONCE so you should get good at it the first time.

[maxnix]

Thanks for the quick tips. breaksr.

[Kierco]

I want to thank all of you folks that chimed in to help me with the plenum / injector removal topic. Even the d!ck wadd commedian with the VVT. We all need a good laugh sometimes to ease the bruised knuckles.I am still a little vague on how to get the lower 2 bolts out of the throttle body.

[Q45tech]

The Snap On Truck is full of expensive specialty tools:

[elwesso]

I am still a little vague on how to get the lower 2 bolts out of the throttle body.

Get an allen socket at sears or wherever. Its 6mm. You can put the socket on an extension.

[ScottJackson]

I didn't have to pull the throttle body when I pulled the plenum. <- that's a serious post and all true, unlike the VVT hydrostatic rod... which is just mostly true and those that don't believe have just been lucky so far. Kinda like how people don't believe in bigfoot until they get eaten alive by a blood thirsty yeti. By the way, that VVT thing was supposed to be nothing more than a light hearted joke. Not making fun of anybody who asks for some tips when doing an automotive job. Asking for advice is a great thing to do and I am in no way trying to belittle anyone.

[maxnix]

that's a serious post and all true, unlike the VVT hydrostatic rod... which is just mostly true and those that don't believe have just been lucky so far.

I was scrambling for my safety goggles.

[breaksr]

Lower bolts on the thottle body. My favorite. Get a 6mm allen wrench (the longest one you can find) and cut off the short side. Now it looks like one long straight piece. Stick one end into a 6mm socket and stick the other end into one of those bolts on the throttle body. Get out your socket tool and turn it loose. Be careful not to break that allen wrench since it is very brittle. When you go to put it back on the plenum tighten them gradually one at a time in cross pattern (upper left first and then lower right etc.). Don't tighten any one all the way until you tighten all the others. Like tightening bolts on a cylinder head. Make sure they are good and tight since you can get gas fumes from there. Now with the money I just saved you buy new gas lines and replace the rubber gaskets between the plenum and the lower intake manifolds.

[elwesso]

Lower bolts on the thottle body. My favorite. Get a 6mm allen wrench (the longest one you can find) and cut off the short side. Now it looks like one long straight piece. Stick one end into a 6mm socket and stick the other end into one of those bolts on the throttle body. Get out your socket tool and turn it loose. Be careful not to break that allen wrench since it is very brittle. When you go to put it back on the plenum tighten them gradually one at a time in cross pattern (upper left first and then lower right etc.). Don't tighten any one all the way until you tighten all the others. Like tightening bolts on a cylinder head. Make sure they are good and tight since you can get gas fumes from there. Now with the money I just saved you buy new gas lines and replace the rubber gaskets between the plenum and the lower intake manifolds.

OR GO BUY AN ALLEN SOCKET FOR $5!!!!

[maxnix]

The Snap On Truck is full of expensive specialty tools:

Ummm....SnapOn. Crack for the tool obsessed!

[Kierco]

Thanks Breaker, think that I am ready to bo to battle. By the way, I want to make it clear that you guys have a great forum. Lots of help and modest humor. I am sure that I will need more help eventually. Lots more stuff to go wrong on my 92 Q LOLhttp://forums.nicoclub.com/zeropost?cmd=reply&id=2193078#zer...93078#

[goody90q45]

[QUOTE=Kierco]Thanks Breaker, think that I am ready to bo to battle.... QUOTE]

Godspeed to you.

[Q45tech]

Now you know blue collars prefer Ice tea ....."SnapOn. Crack for the tool obsessed"