How much vacume?

[Scott Banner]

How much vacume should a stock cam pull? I think I have a vacume leak so I put a guage on and I'm getting 15-16. I thought I heard 20 was normal.

 

[TurboDave]

Mine pulls about 15-16 in gear, idling. about 18 or so idling in neutral.

 

[fly89gta]

Originally posted by TurboDave
Mine pulls about 15-16 in gear, idling. about 18 or so idling in neutral.

yeah i'm about 15 in gear, bout 20 in park

 

[Scott Banner]

So do you think I might have a vacume leak? Car is doing some weird stuff all of a sudden. Poping and backfiring, and my blm's are at 160.

 

[TurboDave]

Originally posted by Scott Banner
So do you think I might have a vacume leak? Car is doing some weird stuff all of a sudden. Poping and backfiring, and my blm's are at 160.

Could very well be a split/cracked vacuum line. Usually in a place that's impossible to spot right away

the high BLM's like that can indicate a vacuum leak or pre turbo exhaust leak. I'd start looking for either.

 

[PaulRV6]

My stock cam was pulling 16-17 in/hg. I too thought this was low for stock cam but guess not. If idle is very low then vac will read lower than if your car is idling higher.

paul

 

[Scott Banner]

I put the vacume guage on a different line and pulled another line and the guage didn't move. I'm guessing that just explained my problem(leak). Now I'll have to start looking. Thanks.