I am just having the worst time locating this damn vacum leak. I have replaced check valve after check valve and hose after hose. Yet it eludes me still. Is there any easy way to do this?

 

Get a can of carb cleaner or wd40, something flammable, and spray it around your engine bay where you suspect a leak may be. If your engine races you found it. Some people will tell you to use water and try to make the engine stumble. There's no source of ignition to make a fire with outside of your engine bay, even though some people prefer water over the other method for safety; if you spray carb cleaner on your headers it will not catch fire, only evaporate.

Start off spraying at the base of your runners and then at the top; vacuum leaks there are pretty bad. After that you need to check all of the hose connections at the rear of the plenum and check for sealing at the throttle body. Squirt the egr valve too, that could be seated improperly.

 

TPI does not have that many vaccume hoses, a complete replacement should not cost much at all. Make sure the brake booster is not leaking also. How do you know you have a vaccume leak?

 

You can use some smooth jawed pliers to squeeze the vac lines shut and tell if a vac leak is downstream.
I have a set of looong needle-nose pliers that work well getting into tight spots to squeeze lines.
If hoses are old and cooked, this may crack them; but if they crack, they needed replacement anyway.

I'll have to respectfully disagree with rezinn abt not being able to ignite carb cleaner off the exhaust.
I personally watched, from close range, a VW (Jetta I think) catch on fire while my co-worker sprayed B-12 on the exhaust manifold.
(He was aiming for the intake runner, but on this eng the intake and exhaust were on the same side of the cyl. Damn forign job!)
Anyway, the fire burnt thru the PLASTIC fuel line in abt 2 seconds and my bay got quite active at that point.
Owner seemed a bit disappointed when he returned to find his car pushed around back with dry chemical residue everywhere.

Anyway, keep it off the exhaust and you'll probably be ok.
A handy fire ext would certianly be a good idea.

Another possibility is an "internal vac leak". They're pretty rare, but often mis-diagnoised when present.
The term "internal vac leak" refers to a vac leak at the bottom of the intake-to-head gasket.
Luckily, they're easy to check for.
Simply pull the fresh air intake out of one valve cover, and the PCV out of the other valve cover.
Plug both holes with palms of hands while eng is idling (much more comfortable on a cold eng). If a vac is felt, you have an internal vac leak.

Remove and plug big vac line going to power brakes. The diaphram inside the booster will fail occasionally and provide you with a nice sized vac leak.

 

you can use propane instead of messy liquids. get a torch and without lighting it wave it around your hoses and if the idle changes you've found where the leak is.