IT starts @ the intake manifold & ends on the front axle.
If your EGR valve is vacuum operated, simply remove the vacuum hose from the valve.
I have a suggestion. You might want to check your vacuum hose, and vacuum switch. My 4WD was inoperable. If you don't use your 4wd enough you can get dry rought on the hose. That may need to be placed, or check your vacuum switch which is located on the driver side in the transfer case. Might need relplaced, or take it off, clean it reteflon it, and tighten in back down. As for the clunking Might want to check it out at a Transmission shop.
The most typical cause of a vacuum leak is a cracked vacuum hose. The hoses get brittle with age, and cracks are common.
pull the hose off the vacuum advance and some of them have a set screw inside the hole.
Any place that has constant vacuum Usually on the back side at the base of the carb.
Section 4-31 of Chilton Book #28160
You have a vacuum hose disconnected or broken. Check under the hood for a small vacuum hose out of place or broken.
my chevy blazer 1984 the air conditioner blows from down side only.
There are many. All hoses get their vacuum from the intake manifold. (plenum)
No.
You can find 1989 Ford F2 50 vacuum hose harness pictures in most service manuals. Many local libraries will have the service manuals.
The best way to repair a vacuum hose on your Chevrolet is to replace the vacuum hose. The vacuum hose is held in place with a retaining clamp on each end of the hose.
It should set a code or two but, check the MAP sensor and the vacuum hose leading to it.
Try looking in Mitchel's OnDemand5 program under Engine Performance/Vacuum diagrams for this vehicle, Hope this'll help.
A person can find a vacuum hose diagram for this car by asking if an auto tech will print one out. It is also found in the cars maintenance and repair manual.
assuming your talking about the transmission modulator...visually inspect the transmission and look for a vacuum hose from the engine to the tranny...
Does it only occur when the engine is cold? There should be an idle valve with a vacuum hose i.e. BMW has a hose that comes from the intake manifold goes down into an electric valve then goes on to the throttle body intake hose. The timing is retarded to help start/idle the engine when it's cold if the hose came loose it will not advance the ignition when the engine is warm.