Vacuum advance diaphragm broken?

[McNick]

Hi!
Yesterday I spend few hours under the hood of my A20A3 with TEC distributor. I found the continuity of air flow between port A and Port B of vacuum advance diaphragm housing while no one of ports has continuity to the atmosphere. So if I close one of inputs with my finger and pump the air to other input - box hold the vacuum. But if I open closed input then the air start coming from other port until I pump the air. It's has no dependecy to which of two ports I pumping.

Does it mean the broken diaphragm?

Thank you in advance.

[cruznz]

yep,sounds like it..........the ports are for retard and advance so they shouldn't leak

[AccordEpicenter]

actually they are both advance but it sounds like youres is shot, id get another distributror at a yard

[McNick]

Can anybody check the continuity on yours TEC-distributirs...
IMHO, If both diaphragms is advance and works like "Binary OR", then in principle this continuity is not necessary. I dont want to pay $40 for new diaphragm with 0-effect after...

[cruznz]

Originally posted by AccordEpicenter
actually they are both advance

hmmm.....care to enlighten me please........:huh:

[AccordEpicenter]

they run 2 advance diaphrams, somtimes 1 is doing the advance, somtimes the other is, but they arent used simultaneously... the computer messes with it from the vacuum control box.

[cruznz]

well,....i'm going to have to disagree with you here,......the twin vacuum diaphram distributor is used for emission controls,for better economy....this controls vacuum advance and retard @ certain engine speeds and loads
Follow a vacuum diagram and you'll find that there is a vacuum port in front of throttle butterfly and 1 behind which are connected to emission control solenoids,(these can vary depending on model)

[McNick]

So, as I understood, I have to replace my really _BROKEN_ diaphragm?

[cruznz]

if the ports aren't holding vacuum,then you'll need to change it

[cruznz]

Originally posted by AccordEpicenter
they run 2 advance diaphrams, somtimes 1 is doing the advance, somtimes the other is, but they arent used simultaneously... the computer messes with it from the vacuum control box.

[cruznz][quote] well,....i'm going to have to disagree with you here,......the twin vacuum diaphram distributor is used for emission controls,for better economy....this controls vacuum advance and retard @ certain engine speeds and loads
Follow a vacuum diagram and you'll find that there is a vacuum port in front of throttle butterfly and 1 behind which are connected to emission control solenoids,(these can vary depending on model)[quote]

Just needed to add something here,...AccordEpicenter , you were right,on some models there is a cold advance solenoid used with some distributors

[lostforawhile]

one is used to retard timing on start up to help make the engine easier to start, I happened to see this old post and wanted to post the right info