DIY, SR20DET Redtop IACV removal. (pic heavy)

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DIY, SR20DET Redtop IACV removal. (pic heavy)

Postby assassin7420 » Sun Sep 28, 2008 7:57 am

Tools needed,

3/4 ratchet

3/4 extensions

Sockets, 10mm and 12mm

10mm ratcheting wrench

Flat head screw driver

needle nose pliers Gasket scraper

Rubber mallet (for those pain in the *** bolts if you have any)



Intake manifold gasketIACV (duh)IACV Gasket

5/16 hose depending on what route you take.

Step one, DISCONNECT YOUR BATTERY!!!! You will be working with open gas. The last thing you want is to ground something and cause a spark.

Now, Lets move to the engine bay....

Heres where the fun starts, Remove you're IC pipe and couplers.

Remove the ground on the Intake manifold,

Next remove the throttle cable from the throttle body,

Disconnect this vacuum line from the front of the throttle body, Depending on where you plugged in your boost gauge will say if you have to remove the second line right beside it.

Remove the bolt on the bracket that connects the throttle body to the engine.

Remove the clip for the tps

remove the hose running from the valve cover to the intake manifold,

Unplug the injectors,

Remove these clips from the metal bracket and unplug them,-

Unbolt any grounds on the intake manifold,

Disconnect the vacuum line running from the brake booster,

Now comes the part where you start playing with fuel, If you haven't driven the car overnight then there wont be a lot of pressure in the lines, But a little will remain.

Disconnect the the fuel line running into the side of the fuel rail,

Disconnect the fuel line coming from the filter, This will be the one with pressure.

Now, Set aside the fuel lines as their not spilling fuel and move you're harness out of the way.

Start unbolting the intake manifold, You want to unbolt it in a star pattern, Starting with the first nut towards the front of the car. I'm just pointing to one of them with the screw driver here.

Set your bolts in order so you can put them back in the same place,

Now, You should have all 8 nuts and bolts out of the manifold (2 nuts, 6 bolts) Gently lift the the manifold up, Take care not to damage the threads on the studs.

Right now you should only be able to lift it off a little bit, More towards the front of the car. This is because there are 2 hoses on the back lower side of the manifold you can see them here.

One is for coolant, The other is for the IACV. I was able to remove one by just unscrewing the hose clap. The other clamp was put in a god awful spot so i just cut the hose. If you cant get to the clap just get some 5/16 hose and cut the ****er in half.

Once that's done go back to the two clips that where bolted to one of the runners, one goes to the IACV, I forget where the other goes. Take the one thats not for the IACV and slip it thew the runners. This way you wont damage the clip or wires when you lift off the manifold. You should now be able to remove the manifold from the engine bay.

Once you have the intake manifold out remove the bolt that holds the tubing for the IACV to the manifold, Its right next to the throttle body.

Once that's done unclamp the hose from the IACV, Then proceed to unbolt the IACV. This is where I used that 10mm ratcheting wrench. The 3 of the 4 bolts are quite easy to remove, The one on the front inside is a little tricky. With my wrench I could only get 2 clicks in at a time, But once you get it loose you should be able to use your fingers.

Congrats, You just removed your IACV! Yay, for you. Now scrape your old gaskets and install in the reverse order.

When installing the intake manifold tighten in the reverse star order you did taking it off. Meaning the first thing you should tighten is the nut on the back side of the engine. The FSM says tighten them in 2 steps, The first time around you want to do 6.9 - 8.0 FT-LB. The second and final time to do 15 - 20 FT-LB

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Re: DIY, SR20DET Redtop IACV removal. (assassin7420)

Postby E7-S14 » Sun Sep 28, 2008 8:09 am

okplease excuse my noob

but what does IACV stand forans what exactly is the purpose for it?

if im correct it allows air to pass through the throttle body when its closed right?

but what doesn't eh acronym stand for?and what does cleaning it out do for your car?

sorry for thread jackbut if i ever need remove my iacv on my srnow i know how

well detailed tutorial.

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1995 Nissan 240sx (daily)
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Postby assassin7420 » Sun Sep 28, 2008 8:13 am

Its the Idle Air Control Valve. Its common for them to get dirty or crack on the sr's Also the idle adjustment screw on the older IACV's were plastic and would strip out very easily.

You could take it out and clean it doing this way, But you might need new gaskets depending on the condition of the old ones.

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Re: (assassin7420)

Postby positron1 » Sun Sep 28, 2008 12:45 pm

Excellent write-up!

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Re: (positron_)

Postby Kalypso » Tue Sep 30, 2008 12:08 pm

indeed, I plan to do this so I can clean out the inside of my intake.

its not as bad as I thought.

nice writeup

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Re: DIY, SR20DET Redtop IACV removal. (assassin7420)

Postby ORICLE » Sat Nov 22, 2008 1:40 pm

so you took the entire maifold off not just the upper manifold?

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Re: DIY, SR20DET Redtop IACV removal. (pic heavy)

Postby voiddweller » Mon Apr 28, 2014 8:39 am

I know this is an old write-up, but it's good and just helped me out. Loved the pics.

One thing that I didn't see mentioned are the brackets under the manifold. If they are still attached, there are two screws on on front bracket, just above the throttle body.

I didn't see them at first and almost ruined some of the stud threads trying to get the manifold off.


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Re: DIY, SR20DET Redtop IACV removal. (pic heavy)

Postby swinter » Sat Jun 23, 2018 5:55 am

Great writeup. Just curious how long this whole process would take an average individual with average mechanical skill.

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