removed: secondary intake butterflys? Bad Idea?

[uncle_louie83]

Well...when i rebuilt the motor...i removed the butterflys inside the upper intake manifold....ive done this on all my honda motors so i figured why not with the nissan. Well i GUESS it was a mistake...car idles low (650 to 750 rpms)...and when drive the car, if i get the motor in upper RPMS...and i put the car in neutral and let the rpms just fall down, the motor will die...i start the motor...and it idles steady at 650 to 750 again and then i just keep driving...i believe this is because i removed the secondary butterflys (SCV). But im not sure though....please give me some insight to this...cause im gonna end up putting it back on if this is my problem...

lewis

[uncle_louie83]

i guess no one knows anything....im gonna post this on freshalloy

[madbouncy]

650-750 isn't a low idle. The manual says the idle should be 700 + or - 50. So you're fine there. Haven't removed mine but I'd say to make sure you don't have any leaks anywhere. Never read about anybody having a problem like that when removing it.

[SMoKeM240]

i removed mine, and all emisions crap and i have no problems

[NismoGreg]

When I blew up my stock ka in my '93, I purchased a de from a junkyard that came from an automatic 240. The automatic ka does not have secondary intake butterflys in the manifold. My motor runs strong and has more power than my other de did.

[uncle_louie83]

mmm...must be the timing then...thanks for your time.

lewis

[s13sr20chris]

did you also remove the rod they move on? if so that could be a vac leak right there.

[Dattebayo]

The secondary intake butterflies are called the SCV.

(swirl control valve)

They control your low end power and can make the top end a little unstable in a stock KA if removed, but that is up for disscussion as I have never done it and lots of people say different things about it.

The CA18DET guys have a similar setup in their motors and they usually just remove those butterflies so they have access to more top-end power (I guess since their displacement is not as large). They are definatly a barrier to a high-power motor.

The S14 motor does not have them so maybe you would want to switch to a S14 manifold if you are considering building a monster engine.

[uncle_louie83]

knaw i left the rod on there...i just turned the idle screw til i reached 900rpms at idle...i like it better at 900.....makes me feel better...the idle screw is almost all the way out now....mmm...oh well....im taking the car home tonight and then ill investigate more into my problem.

lewis

[Dattebayo]

The engine should not be kept at idle that high.

Please lower it, your feeling is not worth screwing up your engine.

[sean8564]

knaw i left the rod on there...i just turned the idle screw til i reached 900rpms at idle...i like it better at 900.....makes me feel better...the idle screw is almost all the way out now....mmm...oh well....im taking the car home tonight and then ill investigate more into my problem.

lewis

For the love of god lower your RPM back down to 700 this is not a RICE Honda it was designed for that idle you will screw up your motor and have to buy another one

[NateDogg]

Please enlighten everyone how having a 900rpm idle will "screw up your motor"?

[SMoKeM240]

mine idles around 1000 and its fine... and how does it ruin it? thats the dumbest thing i heard

[All_Motor_KA]

Some people like haveing there engines more then 2 years...

[uncle_louie83]

how in the hell would a 900rpm idle **** up a motor? only thing its gonna do is just burn more fuel.....when i left the idle at 700rpms and drove the car around....and immediatly let off the gas....the motor would die...and then i would have to restart it or put the car back in gear while i was rolling.....i think something is still wrong with my timing...oh well.....i gotta stop lending out tools....my torque wrench is 35 miles away and it pisses me off when they wont return them in a timely manner so i can work on my own car.

lewis

p.s. none of my motors have ever lasted 2 years....i blew them all up with too much boost...i know this motor wont be in the car for more than a year because ill end up boosting it way too much.