My dohc ZC has huge cams and really doesnt like to idle. The stock honda IAC just doesnt give it enough air to idle correctly so it stalls all the time - even with the idle screw all the way out. I can cheat by cracking the throttle body open a bit - but when you close the trottle at high rpms it takes forever for the rpms to come back down - super annoying.

I run a Neptune RTP ecu with 880cc injectors, a jg sheet metal intake manifold, and bored gsr throttle body. There is no fast idle - its been blocked off. I have to run the Honda IAC on a plate and connect it to the intake manifold via vacuum lines because the JG manifold doesnt have a plate for it.

Question is, can i run an aftermarket IAC? Maybe some GM IAC? Does anybody know one that is compatable with the honda IAC? Is it possible to run TWO stock honda IAC valves in parallel?

thanks,
liam

 

What size lines do you have running on your remote mounted iac?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">What size lines do you have running on your remote mounted iac?</TD></TR></TABLE>

I believe its 1/4 or 3/8 inch hose - more then large enough i think. If i unplug a vacuum source, say to the FPR, the car idles fine.

liam

 

i'm running the exact same idle setup as you, sheetmetal intake w/external IACV using 3/8 hose, no FICV, and neptune RTP, i had to bump up the duty cycle abit to get the idle i wanted

i'm also curious if you can run 2 IACV's off the PWM signal from neptune.. i know some local guys with Autronic who run the stepper motor IACV from toyota's i think, not sure if that has a larger valve

 

The autronic guys don't run the honda iac because the autronic won't control it properly.

You have to use 3/8" line and fittings with a big i.d., and keep the lines short on the remote mount iac. I had one setup with smaller lines and it wouldn't work right. Then i put bigger lines and it still wouldn't work right. Then i changed the pickup source from a 1/8 npt fitting to a 1/4 npt fitting and used 3/8 line and it worked perfect.

 

&lt;&lt;&lt;If i unplug a vacuum source, say to the FPR, the car idles fine.&gt;&gt;&gt;

- Also make sure the tune is right, by unplugging the FPR hose you are raising the fuel pressure and richening the mixture a bit.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lugnuts &raquo;</TD></TR><TR><TD CLASS="quote">&lt;&lt;&lt;If i unplug a vacuum source, say to the FPR, the car idles fine.&gt;&gt;&gt;

- Also make sure the tune is right, by unplugging the FPR hose you are raising the fuel pressure and richening the mixture a bit.</TD></TR></TABLE>

I ment any vacuum source - you could do the bov and the same thing.

Tony1,

I will try to inlarge the ports and hoses and see if that makes a difference, thanks for the help guys. I'll let you know what i find.

liam