CIS presssure test ??? maybe
 

Reading CIS stuff here gave me a thought. This is for a 78/79 but may work for others. Goal is to find a vacuum leak.

Would it be possible to introduce air pressure into the brake port using shop pressure reduced to (15lbs ???. 30lbs ???) and then using soapy water spray along any seam that looks promising. Bubbles are your friend.

It seems to me it would take a good volume of air and you would hear it thru the oil filler and exhaust. :confused:

Ummmmm.... thinking while typing.

Do a leak down test on #1 cylinder in the intake open position. Use a vacuum gage on the line to the distributor (or other port) to measure the amount of air in the injection system to prevent over pressure. Then the soapy treatment.

PS I have used a Snap On smoke machine with good results borrowed from a very liberal friend which I can't continue to do.:rolleyes:

Nobody want to play?

Unfortunately I can't contribute, but I'm looking for a safe, foolproof, cheap way to find CIS leaks so I'll bump you. JW and psalt and others have recommended propane from a torch through a tube directed toward possible leak areas.

Talked to an old Porsche mechanic today and he said, "hell, thats the way we used to do it until we got smoke machines. It's in the manual."

So if you are chasing a leak in the CIS, here is a way to do it.SmileWavy