legacycentral bbs

Some days my car will pull 15 pounds at idle and 10-11 with the AC on. then today it started to pull 13 but still pulled 10-11 with the ac.

Both reading are for vacuum at idle. no vacuum leaks and has a saab intercooler.

When you put a load on the engine there will be less vacuum so unless something is dragging like the A/C clutch or the clutch clutch. Or your timing could be off.

Cam timing or ignition timing?

15 inHg at idle? That's out of spec, should be a solid 19-20 inHg.

Yeah i think i get like 22.

first we need to know where your from.

second we need to know what type of gauge your using and is it reliable.

and last, how positive are you that you have no leaks?

Thanks

My car is only 18-19 hg via select monitor.

also, is the engine warm at this reading.
i see 16-17 on start up and 18-19 when warm.

his gauge could easily be off.

are u seeing steady boost, and what is it on what set up?

I think the boost gauge might be off, when you turn the car off it sits are 1 pound of boost. its an autometer phantom. I have not checked for leaks I dont hear any and the car idles at 700 perfectly.

The altitude where you live can also be a factor. Here at 5000 feet, I'm seeing around 16 inches of vacuum at cold idle, and about 18 when warmed up. I'm sure both readings would be at least 2-3 inches higher at sea level.