Is it possible to have a condition where you do not have vacuum at idle? What would cause this?

 

Cant imagine how that would occur. Are you sure the vacuum gauge is working correctly and is hooked up correctly?

 

No, I didn't look at the car. I was told this was a condition. I couldn't think of a reason why it would happen so I figured I would put the question out there.

 

There's no way the engine can idle without vacuum as engines are really nothing more than air pumps that go bomb. If the engine is running, it is sucking air so that means it has compression. Check your gauge and the vacuum source.

 

I did not mean to insinuate that I didn't understand how an engine functions. I haven't seen the car face to face. It's not my engine. I was talking with someone and they had this issue. I, however, have not owned a stock FD, or even one that was close to stock. Since I had no experience with the sequential setup and its various vacuum lines, I wondered if it were possible that something could cause a "low" or "no" vacuum reading.

 

if his idle rpm is high enough to produce extra air at idle, then, yes?
but his question would be 'why is my idle at 2500' in that case

(assuming he is reading vacuum from standard boost gauge position -- upper intake manifold)

 

It is conceivable that there could be no vacuum at idle, timing way retarded, and a big race port or bridge port, and some load on engine, etc.

But it's unlikely that all these conditions would met.

It's much more likely that there is a problem with the way it's being measured.

 

i don't know about the FD, but there are some ports on the older cars that do not see vacuum (or boost). in fact the classic rookie mistake with the T2 is to put the fuel pressure regulator hose on the wrong nipple, the correct one sees boost and vacuum, and the other one sees only vacuum.

symptom is it basically not running in boost because its too lean