The emissions decal does show it connected to a vacuum source but calling it a vacuum sensor.
I found the vac source missing when I got the car 2 years ago and put one on it.
It seems this as close as it gets to TBI short of pressurized fuel in my mind being it has a tps and ecu controlled metering rods.
I do speak the efi language but this mongrel is a bit outside of that in its own way I guess.
Thing is a weakling on top, but starts and accelerates pretty well short of a slight flat spot off idle.
I still don't get it, on my '87 LG4, there's the same fender mounted sensor and also another one near the dizzy/EGR valve. The fender mounted one does not have a vacuum hose connected the way GM intended. The one on the engine near the dizzy/EGR valve suppose to be connected to a vacuum source, again the way GM intended.
Not my pic but something I found here:
Red scribblings, is this where yours didn't have a vacuum hose connected and you added it? Or are you saying yours doesn't have a vacuum sensor in this location? If I look at your Facebook pictures, it does appear there's a sensor on the engine but the picture gets pixelated when you blow it up.
The CCC layout changed over the years. Early years the MAP sensor was mounted on the passenger fender with a long vacuum line to the carb. Later years put the BARO sensor on the fender and moved the MAP sensor to the back of the intake manifold with a short vacuum line to the back of the carb.
Certainly not unheard of that a crossover year you could get either configuration but I think I've established in an earlier post that your emissions sticker would indicate whether it's early fender or late engine mounted.