Whats the easiest way to troubleshoot vacuum leaks???
10-03-2006, 08:23 AM
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Whats the easiest way to troubleshoot vacuum leaks??? Well I finally found my prolonged vacuum leak thats been going on for a while. Its the the vacuum hose that goes into the front of the intake right behind the TB on the passenger side, my leak was coming out of that little rubber fitting that looks like a dealer part? It was crimped looking and had a good size hole on the bottom side. I took it off and replaced it with 3/8 's gas line. Will this work or do I need emissions hose? The hose fits perfect on the fittings I even hose clamped it on. Well car runs better but still seems like there is a vacuum leak somewere else. What would be the easiest way to check for more vacuum leaks? Is there any other vacuum lines I should look at that are known for going bad? Thanks
10-03-2006, 03:28 PM
#2
see you ported your tb....did you torque down the 3 bolts evenly?, the pcv system tends to be kinda loose on the passanger side....brake booster....map fitings on the back of the manifold....the 10 manifold bolts themselves....egr sytem....air system....check all of those first and then check back
10-03-2006, 04:23 PM
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If you suspect a leak spray a little brake cleaner in the area thought to leak and the idle will change when it sucks it in. Be very careful around hot manifolds or headers for starting a fire while doing this.
Another way is to take a 5/16 or 3/8 vacuum hose about 2 to 3 ft long and hold one end to your ear and put the other end by the suspected leaked area and you will hear it being sucked/leak.
Dave
Another way is to take a 5/16 or 3/8 vacuum hose about 2 to 3 ft long and hold one end to your ear and put the other end by the suspected leaked area and you will hear it being sucked/leak.
Dave
10-04-2006, 08:04 AM
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yeah I went and just tried spraying the brake cleaner on the hoses and so far no leaks found. How do I check the vacuum hoses on the back of the intake? checked my TB again and its equally tightend as well. Also how do you check to see if your egr and air are working properly. I havent recalled hearing that jet engine noise on initial start up lately?
10-04-2006, 08:19 AM
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Vacuum hoses on the back of the intake should be checked the same way.
For the EGR and AIR system, it would be good to have software like HPTuners and you can force the egr or air to come on and check.
For the EGR and AIR system, it would be good to have software like HPTuners and you can force the egr or air to come on and check.
10-04-2006, 01:49 PM
#6
for the egr you probably will need the software....make sure the hoses for the air system are on pretty tight....there pretty easy to yank off.....check the pcv system...also you said that the car is running better, make sure your butts not doing the old "the cars not running good" deal....when the TB was ported, the space where the plate closes wasnt ported was it?.....do you an egr system?
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10-05-2006, 01:11 PM
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AIR only helps cat light-off. Its codes and any
catalyst efficiency, rear O2 codes don't bother
operation any.
EGR if removed dirty (not turned off) will let the
PCM continue to add excess advance at low
throttle, which the engine will no longer like on
account of no more charge dilution. So you may
see ping, or through a history of ping be stuck
down in the low octane timing table.
Checking vacuum leaks by idle drop, is tough
because the IAC wants to fight you and maintain
a set idle. You might want to pull the IAC conn
and prop up the idle somehow else (shim?) so
that any effect is not covered up. A propane
source is another way to go, at least will not
puddle and flare on you and also goes around
corners better than a stream of liquid.
catalyst efficiency, rear O2 codes don't bother
operation any.
EGR if removed dirty (not turned off) will let the
PCM continue to add excess advance at low
throttle, which the engine will no longer like on
account of no more charge dilution. So you may
see ping, or through a history of ping be stuck
down in the low octane timing table.
Checking vacuum leaks by idle drop, is tough
because the IAC wants to fight you and maintain
a set idle. You might want to pull the IAC conn
and prop up the idle somehow else (shim?) so
that any effect is not covered up. A propane
source is another way to go, at least will not
puddle and flare on you and also goes around
corners better than a stream of liquid.
10-05-2006, 02:00 PM
#9
Originally Posted by DomesticLS1
yeah I went and just tried spraying the brake cleaner on the hoses and so far no leaks found. How do I check the vacuum hoses on the back of the intake? checked my TB again and its equally tightend as well. Also how do you check to see if your egr and air are working properly. I havent recalled hearing that jet engine noise on initial start up lately?
nononono! This is bad for rubber/paint/anything but your brakes, ect. It is also messy. I have found that propane is the best way, get a blow torch (little hand-held benzomatic or something similar, or just use a cracklighter, lol). with the car idling turn on but do not ignite your weapon of choice, and treat it like you would break cleaner. No muss, no fuss. It will speed up the idle just the same, but will detect SMALLER leaks as gas, not liquid is involved.
10-06-2006, 06:45 PM
#10
Originally Posted by Stanger88
nononono! This is bad for rubber/paint/anything but your brakes, ect. It is also messy. I have found that propane is the best way, get a blow torch (little hand-held benzomatic or something similar, or just use a cracklighter, lol). with the car idling turn on but do not ignite your weapon of choice, and treat it like you would break cleaner. No muss, no fuss. It will speed up the idle just the same, but will detect SMALLER leaks as gas, not liquid is involved.
10-07-2006, 03:40 PM
#12
Originally Posted by staringback05
how bout you just stick your ear down there....find it the old way, instead of spraying all kinds of crap over your engine
And if you can put your ear to the back of an LS1 engine in an F-body chassis to listen for vacuum leaks, I'll give you my car
