What is best method to find vacuum leaks?
Thread Starter
Launching!
Joined: Mar 2003
Posts: 238
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From: Castaic Lake, So. Cal.
What is best method to find vacuum leaks? My car is running very rich, my LTFT's are maxing out, so I'm going to search for a vacuum leak.
What method works best? Some use starting fluid to hear the engine speed up when a leak is hit, I read someone use butane and the engine will stumble when the butane is sucked in. Is there a better way that does not involve flammable materials?
What method works best? Some use starting fluid to hear the engine speed up when a leak is hit, I read someone use butane and the engine will stumble when the butane is sucked in. Is there a better way that does not involve flammable materials?
I suppose inert gasses would also have effect but there
is not that much risk to using an unlit propane torch as
long as you are well ventilated and it can't build up.
You can use soap bubbles (soap solution in a foamed
up spray) and look for places where the bubbles
disappear quicker than usual.
If you are doing an idle drop / idle jump test I think
you want to pull the IAC (after getting it idling stable)
because the IAC will try to fight any changes and
hide the results of your mixture-based vac leak tests
(carb cleaner / propane / etc.).
If you have a logger software setup then you may be
able to see single-cylinder vacuum leaks by the current
misfire PIDs, if any stand out.
is not that much risk to using an unlit propane torch as
long as you are well ventilated and it can't build up.
You can use soap bubbles (soap solution in a foamed
up spray) and look for places where the bubbles
disappear quicker than usual.
If you are doing an idle drop / idle jump test I think
you want to pull the IAC (after getting it idling stable)
because the IAC will try to fight any changes and
hide the results of your mixture-based vac leak tests
(carb cleaner / propane / etc.).
If you have a logger software setup then you may be
able to see single-cylinder vacuum leaks by the current
misfire PIDs, if any stand out.
