Question. I have never used propane to find vacuum leaks. I always use starter fluid. I understand propane is better but how nuch do you use? Low volume, or a lot of propane. I just don't want to kill myself. Thanks

 

There needs to be shifted tables that set a codes 171/174.
Using any method may not cause a noticeable change in idle because the response the system has is too fast.
Therefore a Scanner to look at the short term table response is the better way.
I would use the starter fluid so there is more control over the direction and area where the leak might respond.
Try it, you may get lucky enough.
Good luck.

 

Much safer to buy or build yourself a cheap smoke generator. Plug it in to a vacuum port and look for the smoke. I built one out of a mason jar, tubing, some compression fittings. Makes it easy to find leaks. As Bluegrass mentioned, you should have lean codes. When I did, it turned out to be a weak fuel pump.

 

I would use WD-40 before I would Propane.

 

How did you make one?

 

https://www.youtube.com/results?sear...+Smoke+machine

 

The propane is used via a regulated valve and wand.

Carb cleaner is not. If the cleaner ignites it will be most likely a flash fire, very bad for eyebrows.

 

Funny but true

 

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Where do you plug in a smoke tester? Any vacuum line or does it matter?

 

Any vacuum port. You may have to block the air intake to keep the smoke in the motor, not pouring through the air filter.

 

In the old-school carbureted engines one of the techniques to using propane for this purpose was to turn in the idle mixture screws a ways so the engine was struggling a bit and running even more lean so the test was more sensitive to any vacuum leaks that were present. Not sure how that could be accomplished in more modern engines though.

 

Would smoke detector smoke in a can work?

 

Yall going to great lengths to find a leak when a Scanner used to look at the short term fuel trim tables for an instant change when the leak takes in a combustible.
The Ox sensors detect the instant change in exhaust content and cause the trim tables to change values.
This is why you very often cannot hear a change in idle speed, but see the results on a Scanner .
The system self correction is too fast.
This is computer controlled fuel injection in the mili second time range for changes.
It has to work that way to control everything at high engine speeds, for fuel, and ignition timing vs throttle opening, load and road speed.
Good luck.

 

Where do yo get one of these bad *** scanners? What do I search for?

 

The Torque app shows that data.

OBD2 Bluetooth adapter and the Torque app for Android. You can do this for $20 if you already have an Android device.
https://play.google.com/store/apps/d...l.torque&hl=en

https://torque-bhp.com/wiki/Bluetooth_Adapters