GUZZLE7

So decided to make this thread to help everyone else out because i couldnt find anything when i was researching this matter so i had to figure it all out on my own.
I took pictures of my intake manifold assembly process to show you all the components and their function, as well as where everything is routed and located.
Im going to explain a little bit about the whole smog equipment delete and everything else. i hope this helps you and if you have any corrections or additions to my information please feel free to comment... And yes i am a hand model

BTW this is s14 intake manifold there are difference in the s13 manifold

So here it is. Nissan really made a cluster F**k underneath this thing





Now i took the lower half off so i could get better pictures of everything



Here are the components:

Idle air control (IAC)

There are two valves on this base. The AAC valve is the one with the red connector and The one with the purple connector is the FICD valve





The larger valve connected to the larger hard line mounted to the lower plenum is the IACV



Idle Screw





EGR valves (Exhaust Gas Recirculation)

The EGR valve is on the right. The valve on the left is the BPT valve



This is the EGR solenoid



This is the EGR temp sensor




PCV (Positive Crankcase Ventilation)









EVAP:

Charcoal Canister


Temp Sensors













Ok here we go


So i took the it all apart to replace all the gaskets and decided to do a little clean up underneath here because Nissan has a whole rats nest of ass underneath this manifold but i ended up not deleting as much as i thought i would because you actually need most of it but i was able to get rid of a lot of lines.

EVAP
Sooo i accidentally broke my EGR solonoid so im going to be replacing this and its not mounted to the back of the manifold in the pictures like it should be. and my hardline going to my charcoal cannister is cracked as well so i decided to say screw it and elimnate the EVAP.
The EVAP system begins at your gas tank and goes into your charcoal cannister then passed your purge valve and into your intake manifold. The purpose of your EVAP system is to relive the fuel vapors i your gas tank. Even though your gas tank is a sealed tank the fuel still turns to vapor and the vapor will build pressure in your gas tank. This obviously very bad because you dont want a 12 gallon compressed tank full of fuel vapor. So they made all gas caps only hold 1-3 PSI i belive but the "government" doesnt agree with fuel vapor relieving into the atmosphere so they made the evap system to relieve that vapor into your intake manifold at heavy throttle conditions or wide open throttle conditions. the vapor gets stored in the charcoal canister until the computer senses heavy throttle then the purge valve opens and the vapor enters the intake manifold. gas caps are still rated a certain psi to relieve the pressure so you can eliminate the EVAP system and it wont do any harm but you will be losing a little but of your precious expensive gas that is now vapor. I dont feel like spending the dough on all the stuff i broke so im saying bye bye.


Heres the charcoal canister that bolts to the radiator support near the air box and has a few different vacuum lines that run off it. It has a material in it that holds in fuel vapor


Heres the metal hard lines (located underneath the intake manifold and pop out next to the throttle body but i deleted them) that the vaccum lines from the charcoal canister go to and connect plum it into the intake manifold on the back of the motor. there is also a few coolant lines and other vacuum lines connector to this ridiculous concoction of ass.





EGR

So EGR is exhaust gas recirculation and its purpose is to reduce NOx emissions. NOx are a byproduct of combustion and they are mainly created due to high cylinder temperatures and heavy throttle. What EGR does is it takes these inert exhaust gases and recirculates them back into the intake manifold to be burned once again during heavy throttle. Everyone is so anti EGR but actually EGR creates a vacuum in the exhaust manifold which helps during valve rim over lap (the point at which both exhaust and intake valve are open at the same time during the intake stroke in order to help more air get into the cylinder), and it reduces cylinder temperatures, which is always a good thing. So i dont understand this whole hype about these guys deleting EGR and getting all kinds or "GAINZ!". I guess no one really wants exhaust gases going back in their intake and EGR valves commonly go out so i can understand deleting them to prevent the possibility malfunctioning.

The EGR valve is on the right. The valve on the left is the BPT valve. The BPT valve activates the vacuum source to the EGR valve based on exhaust backpressure. The hose coming off the bottom of the BPT valve is very commonly burned up and causes EGR codes very frequently.





Here is the EGR vacuum solonoid it controls vacuum to the EGR valve. I broke mine so im going to have to replace it but it mounts to the back of the manifold next to the EGR valve and goes in line with the vacuum lines to the BPT valve.



I ran vacuum off this nipple on the plenum (lower half of manifold)



If you want to delete the EGR you can buy this $10 plate off ebay or make you own. make sure you replace the gasket


Here is the pipe that connects the intake and exhaust manifold


This is the Intake temp sensor it is an input for the EGR Valve operation. it threads into the center of the lower plenum and the wire connector is routed to the back of the manifold



PCV

PCV is positive crankcase ventilation and it is very important do not delete this component. what it does is ventilates all the Blow By that gets passed the piston rings and into the crankcase during combustion. That Blow By will contaminate the oil and cause it to get sludgy as well as create pressure in the crank case until oil begins to blow out of the dipstick tube and blow engine seals. what this system does it creates a constant flow going through thes crankcase that begins from your intake pipe and enters your valve cover than goes through your crankcase and back in your intake manifold to be burned. the KA has some sort of weird baffle and tuned hard pipe that enters each intake runner. not a bad system but it looks like a bunch of stupid crap under your manifold.. this is okay because it is important.

"the PCV valve is actually the "little nipple" that screws into the back of the front timing cover. Those are almost never replaced, because they're a TOTAL PITA to get to and can cause the engine to burn oil when clogged. To get to them in the car you've gotta remove the alternator and lower alternator bracket. If you go to replace this plan on breaking the hose. That hose gets baked like hell and usually breaks on removal. To get to the other end of the hose, where it connects to the pipe, it is best to remove the starter for easy access. DO NOT USE COOLANT HOSE FOR THE PCV HOSES!!! Coolant hose will swell up and deteriorate when exposed to oil. Oil hose or trans cooler hose ONLY!!!" -racepar1

here is the baffle and the nipple (PCV Valve) that comes out of the side of the block and into the tuned hard pipe under the manifold.


here is the tuned hard pipe that branches off into each intake runner



heres the port that comes out of the valve cover and connects to the intake pipe


Idle Air Control

"There are actually two valves on that base. The AAC valve is the one with the red connector and it is the PRIMARY idle control valve. The one with the purple connector is the FICD valve and is responsible for bumping up the idle when the P/S pressure is high lr the A/C is on. Those valves are very common to get FILTHY inside and commonly cause idle issues. ANYONE with a KA should remove that valve assembly, dis-assemble it completely, clean the base and ALL components, and re-install the assembly and re-adjust their idle. The IACV valve is under the mani and is a single valve, rather large. The IACV keeps the idle from dipping when you come to a stop, but does NOT control the static idle." -racepar1
This is a useful thing i wouldnt delete on a daily driver. For race cars you can eliminate this and just adjust your throttle body slightly open to keep your car to idle because your not really worried about stalling while stopped at the race track anyways. there is an idle adjust screw but i always screw mine all the way closed. the more you turn it counter clockwise the more air it will allow in and the higher it will raise your idle. Keep this closed when doing your timing.

Valves AAC FICD


IACV is the black valve connected to the larger hardline




Screw

Temp Sensors

There are two temp sensors that thread into the manifold. the smaller one is for the gauge cluster and the larger one is input for your ECU. The input for your ECU is very important because your ECU wont go into closed loop until it gets the signal that your vehicle is up to operating temperature. Sooo, your ECU runs on two loops, Closed loop and Open loop. The difference is Closed loop uses the input of the O2 senosor and Open loop doesnt. This is very important because your ECU needs to use your O2 sensor input to sense and adjust the air fuel ratio so your engine will run efficienciently. If your vehicle stays in Open loop it runs the engine rich to be safe because it isnt sensing the air fuel ratio through the O2. This in turn hurts your gas mileage and hurts your efficiency and power. So if your vehicle is getting bad gas mileage your temp sensor could be an issue because your ECU isnt sensing its up to operating temperature and wont go into closed loop.

Here are the sensors


this is where they thread


Coolant Lines

So i definitely eliminated a lot of coolant crap. There are 4 coolant ports that come out of the block. 2 are larger in diameter and 2 are slightly smaller. the smaller diameter ports are for your heater core and the larger diameter are a thermostat bypass. you have to loop the thermostat bypass ports together that way the water pump can keep circulating the water in the block until the thermostat opens. There are also two smaller nipples that come off the ports and both of these go to the throttle body. This is for cold starts in cold climate areas so the coolant can heat up the air going into the manifold. very stupid i deleted this. i welded one of the ports shut and cut the rest off.

here is the thermostat bypass looped (larger ports)

top port where theres normally a nipple i got rid of


bottom port in very back closest to block


looped


here is where the throttle body coolant line nipples normally go but i cut them off


heres the other nipple that goes on this dumb thing i got rid of



Heres the first heater core line port. the size of the ports on the engine are smaller than the size of the ports on the firewall for the heater core so i used a size hose that was right in the middle of both. i know your not suppose to do that but i do what i want. im pretty sure the lines can go on either port of the fire wall it will flow the same through the heater core but im puting the return line on the bottom port just because that seems logical.



heres the other pot on back of block


ran both lines out the back and left them long so it will be easy for me to hook up when i drop the motor in


heres the stock hardlines that adapt up for the smaller diameter to lager diameter for the heater core but im not running this rusty crap. its just more potential spots to leak

IMG_5190.jpg Photo by codyscool | Photobucket

Vacuum

I used this port for all my vacuum (located on the center of lower manifold)




The larger nipple goes to your brake booster and smaller goes to your fuel pressure regulator on your fuel rail. dont Tee off your fuel pressure regulator line



dont forget to bolt your knock sensor to the block and run the wire towards the front of the manifold because its a bitch to do once everythings already together. And the knock sensor doesnt sense rod knock. it senses a high pitched pinging in the motor caused by detonation because the timing is to advance so it tells the ECU to retard the timing. The knock sensor is for adjusting timing and allows the ECU to advance the timing all the way before detonation. dont mistake it for letting you know if u have rod knock or not because it wont.











Ok thats all i have for now i hope this helps a lot of people. i know its a mess under there and once you take it all off its hard to figure where it all goes again. If there is any wrong information and you have corrections please comment you wont hurt my feelings. Ive taken a couple smog classes and have gone through schooling for this but im a little rusty.

God Bless and Keep Drifting

Ilya

Wonderful post

YesImLDS

Very informative and it makes me want to get into it and do some cleaning up!

Bellagio

I finally know what the EGR is! This post is hella informative, thanks bro!

mewantkouki

1 minor correction.

Map sensor = intake air temp sensor

Ka oem ecu uses a MAF meter to monitor air. That little sensor on the lower intake manifold is not a pressure sensor.

At first reading through this thread I was thinking: Why is this keeping all of this stupid emissions shit. Then I saw you lived in California.

94spitfire91

Good work I see you put some time into this. Thanks for an actual informative thread Zilvia doesnt get these too often

IROYLE1

I really appreciate this. I plan to use this to rebuilding my intake mani and replace all my cracked rubber. THanks for the post man. Great job.

IROYLE1

One suggestion for things to include are torque specs when replacing components and assembling the manifold.

PPman

Awesome post! Thank you! This should be titles 240SX intake and components for dummies.

dorkidori_s13

Ive made this a sticky. Awesome information! Very, VERY well put together! Thank you for your awesome contribution!

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rebornS14

thank you for the awesome pics

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racepar1

OK, I've got some issues here. There is a LOT of completely incorrect information here. Also, this is an S14 KA. S13 KA's are different under there. That SHOULD have been mentioned.

Ok, this is NOT called the IACV. There are actually two valves on that base. The AAC valve is the one with the red connector and it is the PRIMARY idle control valve. The one with the purple connector is the FICD valve and is responsible for bumping up the idle when the P/S pressure is high lr the A/C is on. Those valves are very common to get FILTHY inside and commonly cause idle issues. ANYONE with a KA should remove that valve assembly, dis-assemble it completely, clean the base and ALL components, and re-install the assembly and re-adjust their idle. The IACV valve is under the mani and is a single valve, rather large. The IACV keeps the idle from dipping when you come to a stop, but does NOT control the static idle.


The EGR valve is on the right. The valve on the left is the BPT valve. The BPT valve activates the vacuum source to the EGR valve based on exhaust backpressure. The hose coming off the bottom of the BPT valve is very commonly burned up and causes EGR codes very frequently.

OK, the PCV valve is actually the "little nipple" that screws into the back of the front timing cover. Those are almost never replaced, because they're a TOTAL PITA to get to and can cause the engine to burn oil when clogged. To get to them in the car you've gotta remove the alternator and lower alternator bracket. If you go to replace this plan on breaking the hose. That hose gets baked like hell and usually breaks on removal. To get to the other end of the hose, where it connects to the pipe, it is best to remove the starter for easy access. DO NOT USE COOLANT HOSE FOR THE PCV HOSES!!! Coolant hose will swell up and deteriorate when exposed to oil. Oil hose or trans cooler hose ONLY!!!

That is NOT the EVAP purge valve. That is the EGR solenoid...

Once again, that is NOT the MAP sensor. That is the EGR temp sensor. 240's DO NOT HAVE MAP sensors, they have MAF sensors. You usually won't see both present on a car of any make. On the S13's only CA cars have those. On the S14's I think they all do.


Honestly man, I applaud the effort, but there is a LOT of mis-information in this thread. Dorkidori really jumped the gun stickying this one. You clearly don't really know what most of the parts are or how most of the systems function. I would advise anyone looking at this for factual information to do more research. There are a TON of things incorrect about what the OP states here.

GUZZLE7

Hey thank you very much for the corrections. Another reason for me doing this, other than helping people, was to figure out the things I had wrong and learn more information about it. Like I said it was my first time. I'll correct it as soon as possible sorry if I confused anyone else and thank you

dorkidori_s13

i stickied this because a thread of this nature NEEDED to happen! i can easily update information as it is corrected

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240sxfan6882

Sir! VERY good job! Very descriptive and awesome photos!

GUZZLE7

thank you for stickying this. I found absolutely no helpful information or threads on this when i was researching so i thought zilvia needed this. Together with my pictures everyone can just add their knowledge to any information they have on it. I already edited all the new information that Racepar1 gave me.

driftheart

This a very useful posting, we need one for SR now, for those that aren't experts on engines. Sometimes doing tons of research and having tid bits from all over doesn't paint a complete picture of the functions and purposes of systems.

mechanicalmoron

I'm pretty sure you have open and closed loop reversed.

Open is when outside data is entering the ECU's decision, that data from the sensor. Closed loop is when the ECU does not factor in sensor info, when making decisions.

GUZZLE7

nope closed loop is when the ECU senses it meets the correct parameters such as engine being up to operating temp and O2 warmed up then it begins to use the O2 signals to adjust air fuel. Open loop is when you first start the vehicle and the engine isnt warm enough and O2 isnt warm enough to get correct readings so it runs the engine rich without O2 input until it meets the parameters

yetijeff

This thread is great. Probably the most well written and thought out "intake manifold FAQ" thread on this site. +1 for you

denian_cellphone

wow thank you very much!!! definitely one of the best threads in a while.

Rb26kouki

Awesome Thread...

DJ-of-E

Great idea of a thread, you got a lot of information that applies to other intakes as well.

But I also agree with racepar1. When I read the OP, I was like "good information...wait a minute...that's not the right part."

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Livid_240sx

Hell yeah thanks guys.

Sent from my SCH-I535 using Tapatalk

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'91 s13 (Drift Rocket Under Construction)
2000 civic Si Coupe (Daily)

waxball88

Add this to the OP?
Modifying Intake Manifold for boost

Remove factory PCV system you have two options.
#1(best way)
To do so; Remove the pressed in fittings(x4) that connect the manifold to the "PCV collector" that then runs to the PCV box on the side of the block. Tap them side to side with a hammer and use pliers to pull them out.

Weld the holes shut. Once you do this you can do multiple things. Vent the PCV box to atmosphere, or like i do, run to a catch can then pre-turbo intake. (6AN hose)

#2(dont have a welder) You can tap the holes and add 1/8npt plugs
(will add pics of my other mani like this tomorrow)

On the waterneck, i also chose to cut off the throttle body coolant nipple, as it just gets in the way. Removing the intake manifold is much easier with this cut off. Also then you don't have to use a hose with a bolt smashed in it.

Thats it for the upper intake manifold.
For the lower intake you can buy an EGR delete from Isis. I had problems with mine sealing so i decide why not never have to deal with it again. Weld it shut.
Weld this hole




Another issue i had with boost leaks was the PRE-THROTTLE BODY to AAC hardline leaking. My Ebay intercooler piping elbow was much bigger than the AAC tube and always leaked. So i had a 6AN BRASS fitting welded to the tube and a 6AN ALUMINUM fitting welded to the intercooler pipe and it has never leaked since.

Seen best here (Forgive my hideous old set-up)
The front port(blue) on the catch can runs to the PCV

RB180sxChris

nice write up!

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TOO LEGIT TO QUIT.....

dezzS13

Just wanted to stop by and say thank you. You've answered a ton of questions with this post.

Scratchoz

I definitely appreciate this topic. This helped me so much. Thanks!

maxgtrblue

Thank you.. +1 on finally understanding what this is.

Question.. Do you have check engine light still?

senger

Soooo much infoooo. +1