Jump to content

vacuum advance line


Crom Cruach

Recommended Posts

Is this the vacuum advance line and the TCS at the bottom of the attached photo, sitting on the valve cover? and does it look setup correctly? Idle is rough when the car is cold, then again it’s 2° Celsius here today. 
26C1CA85-EFC5-4B66-B583-66616CC78E2C.thumb.jpeg.b705564f64512b5c9eda4583341164ff.jpeg
 

DD5CA1AD-C72D-4B64-8E7C-EAA550447754.thumb.jpeg.7d37087c3aa508298e7b7225f4af1850.jpeg

Link to comment
Share on other sites

Those look correct. 2 questions though. 1- The open vacuum port on the carb, by the choke, is it open at all times or does the air cleaner vacuum line go there? 

2- more of an observation than a question. The vacuum line for the modulator, by the vacuum advance on the distributor connected to the intake manifold could be hooked up better. Possible vacuum leak with the angles the rubber hose has to make.

The running ruff on start up could be the 2 things I observed or possibly the choke itself needing some adjustment. 

Link to comment
Share on other sites

17 minutes ago, MC1of80 said:

Those look correct. 2 questions though. 1- The open vacuum port on the carb, by the choke, is it open at all times or does the air cleaner vacuum line go there? 

2- more of an observation than a question. The vacuum line for the modulator, by the vacuum advance on the distributor connected to the intake manifold could be hooked up better. Possible vacuum leak with the angles the rubber hose has to make.

The running ruff on start up could be the 2 things I observed or possibly the choke itself needing some adjustment. 

1. That is connected with a rubber hose to a point under the air cleaner - is that correct?

2. out of my league as I don’t know what some of these parts are you mentioned. Do you mean the sharp Y connection that looks a bit bodged? Close up below…

9D1A81BC-8732-48D7-9897-737FB88602A9.thumb.jpeg.46a40099bc66ddb7e1a3667c15c6b5a3.jpeg

 

I have a Haynes manual on order, I really need it. 

Link to comment
Share on other sites

The little cylinder at the "y" connection is a temp. controlled valve that only allows for vacuum advance once the engine is warm. If it's failed, you won't get any vacuum to the distributor.

The modulator lines are the two coming out of the intake manifold between the carb and distributor, and they look a little aged too. 

If you're not going completely stock, you may want to consider going to an "HEI" ignition system. They're lower maintenance and less prone to the effects of humidity. 

Link to comment
Share on other sites

The fitting coming out of the intake manifold, behind the carb, in front of the distributor and coil. The rubber lines angles could be causing a vacuum leak. 

The vacuum port off of the carb of which I speak, is approximately 3" towards the front of the car, on the passenger side, in front of the "y" in the hoses of which you speak. Should be plugged off if the small hose from the air cleaner does not go there. 

As far as converting to an HEI or electronic ignition I highly recommend a pertronix flame thrower conversion. I have it in my "Barn Find" and other cars with impeccable results! Highly recommend. 

Link to comment
Share on other sites

2 hours ago, Scott S. said:

The cold will do that, but so will leaks in the line. Probably wouldn't hurt to replace them. 

Where does the line exiting the top of the picture lead ?

Scott, do you mean the line that starts from the ’T’ coming out the front of the carb, and is secured to another line?

Link to comment
Share on other sites

17 hours ago, Crom Cruach said:

Scott, do you mean the line that starts from the ’T’ coming out the front of the carb, and is secured to another line?

Yes. Does it connect to the flapper valve in the air cleaner snorkel ? 

Link to comment
Share on other sites

7 minutes ago, Scott S. said:

Yes. Does it connect to the flapper valve in the air cleaner snorkel ? 

The passenger side goes to the flapper valve, and the driver side goes to the fuel (pump?) at the very front of the car. 
what happens with the vacuum hoses when you go full electronic like the PerTronix Flame-Thrower - disconnect the lot? 

Link to comment
Share on other sites

The fuel pump is on the passenger's side of the engine, under the "generator".. lol

So the line goes to a can sitting on the fender well ? That would be the fuel return line.... Early emission control thingy. You can delete this if you're going to switch to header exhaust type systems.

You'll still need the basic vacuum lines on any system. One for timing advance, on the front of the carb, one for crankcase venting. Big one on the front. Big one on the back is for the power brakes, and the two off the manifold behind the carb are for the transmission and A.C. controls. 

If you decide to go with an "open air" intake system, the port on the passenger's side will need to be plugged as well. 

I've never personally used a PerTronix, always found that the HEI system was a cheaper and easier swap, and there are lots of companies making parts for it. 

But that's just me..... ;)

  • Like 1
Link to comment
Share on other sites

Yeah I was looking at an open element cleaner allright! I was initially thinking of restoration, but I might actually try to wake up the 350 with reversible modifications. One criteria I want to keep is the ability to use regular unleaded, as high-octane is hard to find here and I don’t want to fiddle around with additives. I believe that limits my compression to something like under 9:1 but I haven’t really looked into it yet. Maybe that’s for another post. 
 

it’s very addictive! 

  • Like 1
Link to comment
Share on other sites

And it isn't cheap !!! lol

Premium fuel around here is about $ 1.75/liter :(

There are dozens of ways to wake up a 350, Ignition, carbs vs. fuel injection, rear differential gears and overdrive transmissions and torque converters..... Depending on what you want to spend, and the availability of parts. A factory 350 won't do much more than about 4800 rpm's, but getting it to breathe better is always a plus.

Once you get all the bugs worked out, ie. new fluids and filters, new rubber lines, maybe some plugs, wires and points, (if you're staying with the original ignition system for now), you'll see some improvements. But odds are pretty good you've got a differential ratio that's meant for good mileage, which will keep you from getting any real acceleration. 

Any idea of what that might be ??

  • Like 1
Link to comment
Share on other sites

Another thing you might want to look into is re jetting your Q jet carb. 

Montelishi spent most of her life close to sea level, so when I got her out here I found that I could barely keep her running, and you could actually see the fuel dripping out of the exhaust tips due to the change in elevation. (2500 ft. above sea level). 

Just something you could check up on.... 

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...