Bonger

And thanks for the replies guys as well.

BadFish523

Sounds like you're on the right track. If it comes to it the solenoid is usually $25- $30 at the auto man

EBC-150

Under load an engine has the least amount of vacuum. This is also when you'll loose vac to the IWE's if there is a leak in the system or the check valves are bad.

From wikipedia:
"If the engine is operating under light or no load and low or closed throttle, there is high manifold vacuum. As the throttle is opened, the engine speed increases rapidly. The engine speed is limited only by the amount of fuel/air mixture that is available in the manifold. Under full throttle and light load, other effects (such as valve float, turbulence in the cylinders, or ignition timing) limit engine speed so that the manifold pressure can increase—but in practice, parasitic drag on the internal walls of the manifold, plus the restrictive nature of the venturi at the heart of the carburetor, means that a low pressure will always be set up as the engine's internal volume exceeds the amount of the air the manifold is capable of delivering.

If the engine is operating under heavy load at wide throttle openings (such as accelerating from a stop or pulling the car up a hill) then engine speed is limited by the load and minimal vacuum will be created. Engine speed is low but the butterfly valve is fully open. Since the pistons are descending more slowly than under no load, the pressure differences are less marked and parasitic drag in the induction system is negligible. The engine pulls air into the cylinders at the full ambient pressure.

More vacuum is created in some situations. On deceleration or when descending a hill, the throttle will be closed and a low gear selected to control speed. The engine will be rotating fast because the road wheels and transmission are moving quickly, but the butterfly valve will be fully closed. The flow of air through the engine is strongly restricted by the throttle, producing a strong vacuum on the engine side of the butterfly valve which will tend to limit the speed of the engine. This phenomenon, known as engine braking, is used to prevent acceleration or even to slow down with minimal or no brake usage (as when descending a long or steep hill). This vacuum braking should not be confused with compression braking (aka a "Jake brake"), or with exhaust braking, which are often used on large diesel trucks. Such devices are necessary for engine braking with a diesel as they lack a throttle to restrict the air flow enough to create sufficient vacuum to brake a vehicle."

Bonger

- Nope, makes sense. I was aware of WOT being lowest vacuum however I just thought when I was trying to get proper timing through the power curve on an old modded 355 chev small block I used to see the vacuum advance most prominently on loaded, low rpm before she shifted out or was in the wrong gear.

Either way.............I'll get to experimenting since I think she's allowing some vacuum in 4x4 which is disengaging my IWE slightly and tearing it up.

Thanks again all!! I'll report back as things unfold.....