we just installed a Skunk2 intake manifold on my friend's D15b. it's reving at 4k and starts to climb. the throttle cable isn't tensioned so it's not that. there's no vacuum leaks at all. what could be causing the extremely high idle?
anything will help, thanks

 

Did he use all the same parts that were on it before. Does the TB line up like stock.

 

You have a vacuum leak.

Did you install a new manifold gasket? Did you install the correct manifold gasket? Throttle body gasket? Is this an OBD-1 or an OBD-2 D15B? Did you bleed the cooling system to eliminate air pockets in the IAC valve coolant lines?

 

all the parts are right off the oem intake manifold. it has a new intake manifold gasket and a new throttle body gasket. it is an obd1 engine. everything is plugged. we had to stretch the IAT sensor since the d15b has the sensor on the back of the manifold whereas the Skunk2 is on the side. otehr than that, everything is plugged right

 

alright... still no luck. we found a vacuum leak. the line going to the brake booster had a crack. after fixing that leak, the engine is still revving around 5k. it is making a strange whistling noise from the throttle body, but the throttle is completely closed... we took the throttle cable off to make sure

 

Why did you post:

 

I'd take that throttle body off and recheck all its gaskets, vacuum line routing and so on. Use new lines too, if you're pulling some cracked ones off.

 

if the car still has cruise control, double check to make sure you attached the throttle cable and the cruise control cable properly in the right places on the throttle body.

 

Can you actually see that the throttle plate is resting where it is completely shut? Even with the cables off, dirt or other stuff may be keeping the throttle plate open a bit.

 

Did you clean out the throttle body with carb cleaner while it was off?

Did you install the throttle body gasket in the correct orientation?

 

did the manifold have air injection holes in it like the edelbrock performer x manifold had? if so they need to be plugged.

 

im having the same exact problem with the skunk2 pro intake manifold on my d15b vtec obd1, but i also changed to a bwr throttle body and golden eagle fuel rail. My car is idleing at 3-5k and the idle is jumping up n down. We changed to my stock z6 intake/m t/b and fuel rail but its still idling high and its jumping up and down. Is there any tips you guys can give me on wat else i can do we checked vacum lines anit freeze was bleed and i found an extra port of where anti freeze flows out and we r T-ing it off with another line but still no difference. All out of idea last thing is should i just get my p28 chipped but im not sure if that will fix the idle problem

 

Have you tried a new Idle air control
Make sure you didnt mixed the Tps with the map sensor
And make sure you have the canister lines correct

 

Is the throttle cable adjusted too tightly?

 

no we loosened it and still nothing we cant figure it out it was rev way to high i ended up switching it back to my z6 intake mani t/b and fuel rail and it works fine but i will try again jus hoping i can get this to work on this motor. any other suggestions on wat i can do?

 

the factory throttle body can not be used with the pro series intake, its too small. it lets air from being diverted to the iac be bypassed directly into the manifold.