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Typical Vac leak locations?

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Old 05-05-2007, 06:14 PM
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Typical Vac leak locations?

So I'm idling low, about 500rpm. I figured there was a vac leak, so I tested.....15 in.Hg. at idle. That's definitely low vac. Are there any typical vacuum leak locations that I should check first? I stared at the maze of vac lines for about 15 mins and became totally overwhelmed by it all LOL.
Old 05-05-2007, 06:34 PM
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3.0 v6?
Old 05-05-2007, 09:36 PM
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yes, im assuming that is a 3.0 as they have a huge maze of lines, much mor ethan the 22re.


check the main ones first.
all lines going to any part of the intake system
and check your power booster line.

check where the intake pipes connect and your air filter.
Old 05-06-2007, 08:27 PM
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an easy way to find vac leaks is with starter fluid, spray it on your vac lines and if the idle surges you found it
Old 05-06-2007, 10:49 PM
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What the hell is starter fluid

since I would like to find if I had any leaks
Old 05-07-2007, 02:20 AM
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Originally Posted by Jay351
What the hell is starter fluid

since I would like to find if I had any leaks
Either/starting fluid.. Go to any parts store and ask for starting fluid.. They will know.. But you can get it almost anywhere.. Freds, Walmart, ect..
Old 05-07-2007, 05:15 AM
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Originally Posted by 91muddog
yes, im assuming that is a 3.0 as they have a huge maze of lines, much mor ethan the 22re.


check the main ones first.
all lines going to any part of the intake system
and check your power booster line.

check where the intake pipes connect and your air filter.

intake pipe is new and not cracked (yes the stocker was cracked horribly, but that wouldn't cause a vac leak as much as just rough idle and probably stalling due to losing metered air).

Where/what is the power booster line? Gonna have to check the vac diagram and see if I can figure it out.

I have oil leaks at the valve covers, but they're not serious enough for me to think that they're the cause.
Old 05-07-2007, 06:04 AM
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A better (less messy) test is to use an UNLIT propane/MAPP gas torch; run it around all the hoses. If the engine idles up, you have a leak at that location. Don't stop at one; check the entire mess.
Old 05-07-2007, 09:56 AM
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Hairspray works good too to check for vac leaks. Maybe I'm wrong, but I thought vac leaks causes your rpms to increase not decrease.
Old 05-07-2007, 10:44 AM
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Negative, vac leaks cause lower/unstable idle.
Old 05-08-2007, 05:02 PM
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welp, visual inspection of all lines led me nowhere. They're all intact, not cracked or anything. hmm.
Old 05-08-2007, 05:57 PM
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a fog machine works well to just stick it in the TB with the motor off
Old 06-11-2007, 08:28 AM
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Chimmike

Not sure if you found your problem, but I has a similar issue and I found that a vacumn line to my flow control valve (on the power steering pump) had a crack. It wasn't the vacumn line. The valve has two nipples on it, one of the nipple was cracked.

Something to check.. I had to get a valve (95 bucks from toyota) but idles great now.

osr436
Old 06-11-2007, 06:11 PM
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The hoses going to
From the ADD valves and canister, Down to the front diff.
Hoses going to the power steering idle up valve.
Hoses going to the AC idle up VSV/valve/switch.
Bad Pcv hose.
Stuck open EGR valve.
Check all the VSV relay/valves, they can get stuck halfway.
Check FMS valve (I thik thats what its called) on back of engine, Hoses go from black canister on pass side fender near firewall to the valve then to the TB.

These are other things to check if your absolutely sure the ISR connectors are hooked up right.

How about just turn the idle up?, The idle screw path may be getting plugged in the TB.
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