Does anyone know why my cars idle would dip down to 500 rpms, and pop back up to normal idle of 650-750 rpms
This happens when i press the clutch and put the car into neutral when coming to a stop or if i rev it in neutral aggressively, it does the same thing
Also i have a injen CAI there are 2 holes in it, one connects to the head, the other one i dont know what goes there could this be the problem?

 

I get this when my A/c is on its just to slow in adjusting the level (idle valve) cleaning it helped. But your sound like you might have a bad valve, Tps sensor, vacume leak, or miss adjusted valves (this helps trust me). I would take the idle valve off and clean it use throttle body cleaner not brake clean. Also clean the throttle body. Adjust the valves (only adjust dead cold). and check for a vacume leak (hoses, injector seals ect.) tps sensor is more difficult to check as you need to watch voltages. but that would mostly set a code. But so would a vacume leak if it was big enough.

 

Im almost positive that second hole on your cai plugs into a vaccum line right next to your EGR. If that line is blocked off it can cause a serge. I did with me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Acidcrakker &raquo;</TD></TR><TR><TD CLASS="quote">Im almost positive that second hole on your cai plugs into a vaccum line right next to your EGR. If that line is blocked off it can cause a serge. I did with me.</TD></TR></TABLE>
can i get a picture???

And i cleaned the idle air control valve, it didnt help any
But i do think i need a valve adjustment, im finding it hard to find a mechanic that can do it. All the mechanics keep telling me is that my valves cant be adjusted

 

Okay I got some pics on hand



Now they are pics with the hose connected. You might see a little black cap on yours

 

i dont see that, i have jdm h22a

 

Oh

I didnt know that, but you still should have that hose I would think.

 

okay it is the starting air valve thats where the vac line comes from but i cant find it

 

Did you buy the car modified already, if the thing that it connects to is the EGR( I have been trying to figure that out for days now) If you did, it might have an EGR block off plate, installed.

 

could be worse...

mine upon startup revs to 2600 rpms... and does the rev & dip...

onyl a handful of times has it idled at about 800-900rpm.

 

The valve in those pictures is the 'Starting Air Valve', and it's purpose is to just allow a small amount of air to bypass the throttle plate to assist engine starting when you crank the motor, and so shouldn't have any real effect on your idle. It was never fitted to the JDM VTEC Preludes, but was used on the UKDM, USDM models and the 2.3L Ludes IIRC. The JDM lude just has a small blanking plate where it's meant to go.

To the OP, your problem certainly sounds like a classic IACV problem. If you have already tried cleaning the valve out, it may be worth trying to swap it for another one.

 

Okay, i looked at all the VAC lines coming out the Intake manifold and found that the vac line which goes to the Intake Air Bypass (12) was disconnected and it looked like at the end of the VAC line that goes to the IAB had a broken tip stuck in it. If this thing is unplugged what will happen?? If i am unable to connect this line what effects will it have on the car?
And does anyone have a picture of the IAB solenoid on the Intake Manifold?

 

hears a pic of the vacuum line
Its coming out the back of the Intake Manifold on the driver side

 

common guys
If my IAB box isnt plugged to the intake manifold, do the IABs remain open, or closed?


Modified by LukieLuc at 2:27 PM 10/3/2007

 

You really should buy the service manual for your car and motor. Its well worth it. Helms, or even Chiltons.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LukieLuc &raquo;</TD></TR><TR><TD CLASS="quote">common guys
If my IAB box isnt plugged to the intake manifold, do the IABs remain open, or closed?


Modified by LukieLuc at 2:27 PM 10/3/2007</TD></TR></TABLE>

iab are sprung open and vacuumed shut, without anything plugged in they will stay open.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Acidcrakker &raquo;</TD></TR><TR><TD CLASS="quote">You really should buy the service manual for your car and motor. Its well worth it. Helms, or even Chiltons. </TD></TR></TABLE>
I do have the service manual, on my computer in PDF form, it tells you how to trouble Shoot IABs, nothing about what will happen if you dont have them plugged

 

Mabey i was mistaken, I thought you were trying to figure out where the hose in your picture plugs into. Well I wish you the best of luck with that Idol Serge.