DIY KA24DE intake removal; idle fix;

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addisonblck
Posts: 710
Joined: Tue Dec 04, 2007 6:16 pm
Car: 93 se mods soon to come
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year: 1992
engine: KA24DE 5spd
Problem: Unknown vacuum leak; Injector failure; Lights dimming; Erratic idle; White smoke from tail pipe.

I have pictures of the intake removal but not most of the other stuff. Run down on the car's history: I bought the car with a dead cylinder. The 'mechanic" that owned it before me took a lot of shortcuts and ghetto rigged a lot of things. I've been running behind him to fix it all.

List of fixes....

1. Lights dimming
If you think you have bad ground connections, fix them before you do anything else. Bad grounds can cause a litany of problems everywhere. I bought a few grounding cables from Autozone. I attached a ground from the battery to the chassis and another from the battery to the engine. I also added another ground at the back of the engine to the firewall. While adding all of these extra grounds, I took the liberty of cleaning all the existing grounds with a wire brush.To check your work, use a mutlimeter on the ohms selection, to check continuity between 2 points. It should read under 2 ohms. This fixed the dimming problems as well as a hesitation problem I was having at WOT.
2.Injector failure
Fix your grounds if you tried to skip ahead!!!! I repeat this because I did not fix the grounds first and it cost me 2 injectors. Check the ground connected to the head and clean it if its crusty. Its located on 1 of the intake bolts. We'll see it later and I'll remind you. I removed all 4 injectors and replaced the o-rings and rubber seats. Make sure that when you remove these, you are gentle and do not damage the tops. I used a modified vice grip with a flat mouth on it. Lube the o-rings before you try to install the injectors because they will most likely rip. (Once again.. do as i say not as i do :tisk: ) The o-rings fixed the stalling at red lights but adversely raised my idle.
3.Vacuum leak; Erratic idle; White smoke
I took some brake cleaner to find out where my leaks were coming from. Spraying brake cleaner around your engine will cause the idle to raise when it hits a vacuum night. Be careful though because brake cleaner is flammable. It turned out, mine was leaking from behind the engine. Upon disassembly, I discovered the Swirl control valve to be faulty. This lead me to remove my intake manifold so i could remove the secondary butterfly valves.

Lets get into the pics...
Disconnect the battery....yada yada... if you dont know the basics...stop and find a buddy who can teach you some stuff.
im not going to break each pic down because im too long winded. I'll point out important stuff.

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remove these pups
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and this hose coming from the brake booster.

Remove the harness and pull it out of the way as much as possible.

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open your fuel cap to relieve pressure then remove the fuel rail and get it out of the way.

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pop all this crap loose. watch out for rad fluid.

not even gonna lie, Im about to be late for work and dont have a lot of time to finish this right now.
The speedy version... loosen the bolts conncting the upper plenum to the lower then work on the bolts conncting the intake to the head. once this is done remove the bolts connecting the two intake halves. there will be a few random clips and hoses still connected to the lower so be careful while pulling it out. the top should come out easy and the bottom will be a butthole but it WILL come out.

egr removal.... i took every vacuum line out with the exception of one to run to the fuel pump reg.
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no more of this crap
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and no of this. those are the buttery valves. block off the whole that they leave or you'll be in the same boat as before. block any unused vac lines and if youre keen to, take out the charcoal filter. trace the metal tube that runs from it to the gas tank and bend it up towards the hood of the car. once its all said and done, you should have one vacuum line left.
put it all back together... all of it.

i took out a lot more stuff that isnt pictured or mentioned. ill get back on later to clean this up and make a list of all things removed.


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gnubberlang
Posts: 37
Joined: Sun Feb 16, 2014 3:57 pm
Car: 1995 240SX SR20DET
2004 Frontier 4x4 Crew Cab 5-Speed
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Nice. Looking forward to the finished write up.

One question/comment though - I think the best way to depressurize the fuel line is to remove the fuel pump fuse/relay and run the engine until it runs out of fuel pressure and stalls. Someone please correct me if I'm wrong there...


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