wayfarer

iTrader: (5)

2007 LSJ.

Just started it up after a way over extended down time (mods and tune), and I noticed a vacuum hiss / leak at idle. It's coming from the foam covered vent on the boost bypass solenoid. I verified that the vacuum hoses themselves are not leaking, and that they are hooked up correctly.

the idle hunts pretty significantly right now, new tune, injectors and all, and I can see the bypass valve rod at the supercharger rising and falling with the idle oscillations. not sure if this is related to the solenoid or not at this point, but figured I'd better mention it.

if I unplug the electrical connection the vacuum hiss stops.

I also verified that the wires are in the plug correctly.

so-- the question -- is this normal / proper function ?


I don't remember it doing this before, and it just doesn't seem right to me to have an unmetered vacuum leak at idle.

wayfarer

iTrader: (5)

I have gone on to check vacuum at the bypass actuator--

at idle, under bypass, with the solenoid plugged in, there is no vacuum to the bottom of the actuator. Unplug the solenoid, there IS vacuum to the bottom of the actuator, and the supercharger is then in boost, or more accurately, the bypass is closed.

everything is working correctly, at least at idle.

my question remains-- is the solenoid supposed to create a vacuum leak under bypass?

can some of you LSJ guys fire up your car, and at idle -- stick your ear down by your bypass solenoid to verify if you hear a vacuum hiss at idle?