I've tried everything and I just can't find my vacuum leak. I know I have one cuz it does the switcharoo under a load. I don't know what else to do. Anyone know if there is a spray or something?

 

WD-40 will help track it down. The idle will drop when it gets sucked into the leaking area.

 

i've never had much luck spraying wd40 or carb cleaner. i've never used one, but there is a handheld suction thing-amajig that you stick in an individual vac line and pump it a couple of times to pull a vac. it has a gauge that shows the vac pressure and if it doesn't hold, then you've found it. i'm looking on internet for a picture...

well, its kind of pricey.. $120. i wonder if you can rent one.
http://www.amazon.com/Goodson-DVC-10...p;s=automotive



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well if you find it let me know where it is cause my truck does the same thing and i can't find it either

 

Do you meen the heater/AC vents switch under load?

 

Yep. Thats the one.

 

Mine did that. Mine turned out to be one of the vacume check valves by the firewall on the passenger side. That is very common. I just took mine off and blew through them. You should be able to blow through them one way, but they hold air the other way. Cost less then two bucks.
Another common problem is just under the battery tray. Acid can drip down onto the vacume canister and cause a leak in either the hose fitting or the canister.

 

I've heard about under the battery tray. I checked it, but I didn't look good enough I bet.

 

i know you have a 2WD but for others that are having the same problem have have a 4X4... mine was the two hard lines coming from the tcase to the CAD on the D44.. rotted a hole right through one of them and cuased me a switcharoo problem lol

 

Where was the hole shott 8283?i have a 4wd and am loosing vacumn also.i have somewhat solved the problem by adding a second check valve in the line,running through firewall to vacumn cannister.but am still loosing vacumn somewhere.