vac leak, but where?

[Omnivore30psi]

car is running with 10 in Hg at idle. Is it just me or is that a little low. I believe I should be around 20. I can't find a vac leak anywhere, but that's really the only thing that could cause this right? It's running really rich right now too - probably due to the vac leak. Any ideas as to what could cause this?
Thanks in advance

[22dodge]

low vacuum can be caused by incorrect cam timing, ignition timing, bad map sensor or restriction in the map line, bad valve, bad rings... there's a whole bunch of mechanical problems that cause low vacuum readings none of which have anything to do with a leak.

[Omnivore30psi]

I ruled out cam timing already. It was running fine, then I did new fuel lines and now its running like crap. I checked the vac and it was at 10. I'm assuming my map didn't just all of a sudden go bad right after I did this, same with my internal engine components (rings, valves, head gasket). Any other ideas? I need to be at work at noon, thinking about calling in.

[abiba_69]

So, if you THINK you have a vaccuum leak and need to check, i just unplug my MAP sensor and take a drag of a smoke. If you don't smoke, get a buddy! Then blow the smoke into the vac hose. If you have a leak, you should see the smoke. That's just me tho!

Good luck

[Omnivore30psi]

I like that idea. I don't smoke but I think I may buy my first pack today just to do this.

[tryingbe]

Spray carb cleaner around the vaccum lines, the engine will blog when you're spraying near the vaccum leak.

[detobias]

Quote:

Originally Posted by tryingbe Spray carb cleaner around the vaccum lines, the engine will blog when you're spraying near the vaccum leak.

LOL sorry but the engine will "blog" ? that's funny

anywayz not sure what engine you have but is its stock, the 3/8" vac -> 4 plastic vac line part (attaches right to intake mani) is a very common failure point ; one of the 4 or 5 plastic lines plugged in there can get pulled partially out and wont be obvious but will be leaking like a sieve

if your only running 10" it sounds like a *huge* leak ...you may have jumped a tooth on cam timing , how tight is your cam belt ?

you said you worked on fuel lines - did you mess with the charcoal canister? that has a large vac line to it and may cause a vacuum drop of that magnitude if open

otherwise pull every vacuum line off and plug every single orifice ; do you still have low vac ? then its internal (cam timing or a whopper of an intake mani gasket leak)

[Omnivore30psi]

yup I think I may be zero-ing in on the problem. I have to work today, but when I get out later I'm going to check cam timing again just for the heck of it, then replace every single line. I like the carb cleaner idea too. better than $5 for a pack of cigs I wont even smoke.