Electronic ignition vacuum advance pipe

[trchris]

Hi All

Those of you using fully electronic distributors are you still connecting the vacuum advance pipe ? if so are you using a vapour trap or just connecting direct? been running mine disconnected for a long while and have been wondering if it should be re connected both ends are blocked of course  

Chris  

[stuart]

Just now, trchris said:

Hi All

Those of you using fully electronic distributors are you still connecting the vacuum advance pipe ? if so are you using a vapour trap or just connecting direct? been running mine disconnected for a long while and have been wondering if it should be re connected both ends are blocked of course  

Chris  

If its a 123 type then a flame trap is required if your going to reconnect it. I would imagine this would apply to other types as well.

Stuart.

[trchris]

Hi Stuart 

That's what I thought I will have to hunt the auto jumbles for a flame/ vapour trap before re fitting

Chris  

[stuart]

36 minutes ago, trchris said:

Hi Stuart 

That's what I thought I will have to hunt the auto jumbles for a flame/ vapour trap before re fitting

Chris  

Theyre easily available new which would be a better bet. Standard fit on MGB.

Stuart.

[RogerH]

Hi Chris,

 this was forwarded to me from my friend Tom

I have the '123' distributor fitted to my TR3A and is connected to a vacuum pipe with a vapour trap.

This is really essential to prevent any fuel entering the distributor which will completely ruin it.

The vapour trap should be fitted as shown in my photo in as near (upward) vertical position.

Vacuum pipes with a vapour trap are available from Moss. There are two types depending on the end fittings.

My vacuum pipe has a push on connection to the distributor.

 

Roger

[BRENDA1]

Looks like I will have to get a vapour trap for my 123 distributor, I’ve had Brenda 12+ years and it not had one fitted, just had a look at the paper work for distribution and dose not mention a vapour trap.

Mike redrose group 

[Z320]

I have doubts about this,

can‘t find a matching physical explanation.

[AndyR100]

I contacted the 123  manufacturers about this question last year - they replied that a vapour-trap was not needed. Obviously, fitting one isn’t going to do any harm and may prevent problems if they are wrong (I didn’t fit one)

….. Andy

[Z320]

This is a vaccum pipe from the distributor with no flow of nothing to the carbs.....

[trchris]

Update

Just had message back from CSI regarding vacuum pipe have been told no need for vacuum advance pipe to be fitted however do not block off distributor 

Chris

[Andy Moltu]

Would the diaphragm in the vacuum unit not prevent fuel/vapour entering the main body of the dizzy where the electronics are?

[Z320]

Yes,

but the carb sucks on the vacuum pipe and vacuum unit, how can vapours get to the distributor?

Btw a question about the vacuum pipe with vapour trap:

if the trap would make sense, what to do when the trap is full (full with what)?

Edited March 6, 2022 by Z320

[Andy Moltu]

I would think it only sucks whilst the engine is running so vapour may well go the other way when the vacuum falls on stopping.  However the diaphragm on the vaccum unit should act as an effective barrier to vapours and flames going up the pipe.