So I've got my ICV disconnected (both ports capped off) and I *swear* I'm getting much snappier boost and throttle response.

Now I can understand the better throttle response, as if the ICV is opened partially all the time, then by capping the ports I'm forcing ALL the air through the throttle plate.

But does it make sense that the boost response is quicker too? Seat-of-pants tells me the car is stronger.

I guess I should take some logs and compare acceleration times.

 

 

I knew a guy who did that too, and he said besides the few minutes to let it warm up, it ran way better. So maybe

 

Has the weather gotten reasonably cooler, during this period of time, where you live?

 

It was probably leaking, don't you think?

 

Sounds like a leak to me.

 

Yeah I was thinking it must be leaking. I keep thinking, "But the ICV is new!" but then I realize that I replaced it a few years ago.... and I've put over 50k on the car since I've owned it, so it's entirely possible the ICV is just bad.

What's strange though? I did a pressure test right before I put the car back together last weekend (lifter failed, just swapped the whole cam tower) just to make sure I didn't miss any hose clamps, etc. and it had 0 leaks. So if the ICV is leaking, it must only be leaking under vacuum. I pumped the entire system up to 15psi and it was quiet.

 

I think if you pressure test the intake, you're going to have the same pressure on both sides of the ISV (as opposed to when the engine is actually running); so you wouldn't notice a leak in that case.

 

Under heat and or actual load it can be a completely different story. did you check those ICV lines and the nipple/pipe that sticks out of the intake manifold.