is this a valid way to test fuel injectors?

[Obin Robinson]

ok, i took all 4 injectors out of the 944 and i cleaned them in my ultrasonic cleaner for about 3 minutes each. i used a mixture of ammonia and water (i looked it up and it was safe) and there was indeed some junk in them.

i got a length of rubber hose and hooked it to the nozzle end of the injector. i then attached it to my little vacuum tester. i pumped it up to 27.5 inches of mercury vacuum and i lft it for a while. i am going to see how much the pressure drops in an hour, if at all.

in theory, if the pressure doesn't drop then this is an airtight injector... and therefore it's not leaking right?

here's a pic of my ghetto injector leak tester:


my question is:

is this a valid way to test for leaks on a fuel injector or am i not creating enough of a vacuum to test properly?

offhand, i found this which might interest some people here:
http://www.affordable-efi.com/fuel_injector_cleaning_service.htm

also, while cleaning the injectors ultrasonically, i opened and closed them using two 1.5 volt AA batteries in series. woked fine and i got some microscopic dirt out from inside these injectors.

any input would be greatly appreciated!

thanks!

obin

[AFJuvat]

Well, it isn't exactly "by the book" Then again, going by the book would cost you several thousand dollars in testing equipment.

I would venture to guess that if you can hold a vacuum you should be in good shape.

I would still flush them out (backwards and forwards) with carb cleaner followed by brake cleaner.

AFJuvat

[Obin Robinson]

i'm sending my injectors here:

http://www.affordable-efi.com

i'll fill everyone in on the results when they get back

obin