Hi All, just replaced the heads, intake manifold and carb on the car and I have a vacuum line that I am unsure of its purpose, and hoping someone can identify it. unlike the other rubber lines running from the distributor to the carb etc, this one is in the form of a thin hard line that ends up terminating on the intake manifold with an adaptor on the end for the same size rubber vacuum line as you would use for the distributor vacuum connection

Wondering what it is and if it should be connected to ported or manifold vacuum source? I can't seem to find any reference to it. I initially thought that it might be trans related, but apparently the 700r4 has no vacuum connections.

This car had an LG4 and CC Qjet originally, but has been running a 600 CFM Holley on the 350 sbc for the past 15 years. I have now changed to an AVS2 650 CFM carb. All of the smog , air con and cruise have been removed.

Cheers.

 

What model, year, and optons?

It could be anything from a source for cruise control or HVAC dampers to EVAP purge or AIR diverter valve.

 

That sounds like the vacuum line to the charcoal canister for the gas tank vent.

 

Got any photos?

 

Thanks all for replying. It is an 83 Berlinetta, originally with LG4, Air-con, cruise control, cc qjet carb.

Here's a pic of it.

 

It Went To The Rear Of The Qjet

 

That should have connected to the VAC sensor. (1984 diagram)

 

Yep, that's the one! Looking at that carb brings back memories...

 

Thanks for confirming that, much appreciated. So it is just a reference for the ECU? The computer is still in there, would it be using this data for anything transmission related?

 

Only torque converter lockup, but that should have been addressed a long time ago.

 

I recall installing a B&M 4th gear anti kickdown kit about 20 years ago, lol but don't recall doing anything else with the trans. I'll hook it up to manifold vacuum and see how it goes.