Yes, the link that wyckedcombo17 posted has some excellent photographs of the dis- and reassembly process. My plan was to dissasemble according to those instructions, let sit overnight, and rebuild/reinstall tomorrow. My trip to NAPA will include a vacuum gauge, carb cleaner, and hopefully a tach that I can install to help get the engine running like a top. The dist cap and rotor, plugs, and wires have less than 100 miles on them (PO installed), so I worry less about those than I do the carb and tuning.

Nathan, you had mentioned that you may have the carb settings for a 390 as my kit doesn't have those settings included. Any chance you were able to find them?

Fish

 

Ah yes, the instructions... Well the leftover parts from the carb rebuild kit with the box and instructions found it's way into my office and it found it's way into the trash. My super efficient wife emptied the trash in the office (usually occurs once every 2 months) and yesterday was garbage day so unfortunately it is gone, sorry.

If you don't already have one, the nicer timing lights have a tach function as well. You could use this to set your idle speeds and such and not have to worry about trying to mount a dash mounted tach. I would love to have a tach on the inside but a good one is several hundred $ and I don't really have a good place to mount it so I just use other things.

My dad had an old dwell meter which would function as a tach, voltmeter, etc. I have used it, and I have used my friend's really awesome timing light too. Both work equally well and are actually handier than trying to read an internal tach while I'm under the hood.

 

Disassembled and soaking now. Removal and disassembly really wasn't that hard at all. Interestingly, the back left bolt holding the carb to the intake was less than finger tight. I wonder if that had something to do with the intense fuel smell coming from underneath the hood.

Fish "soaking overnight to rebuild tomorrow" Scientist

 

The diaphragm element from the accelerator pump on the left in the photo is the element that came out of my carb. The element on the right is the one that came out of my rebuild kit. They are vastly different. Should I use the original, or try to make the new one fit? I won't start rebuilding until tomorrow, so I've got time to figure it out.



Also, there was a hose that leads to nowhere, right next to the choke pull off. Any idea where this hose led? Should I plug it up when I reinstall?



Thanks -

Fish

 

Not 100% sure what that is for, ive always just capped it off, i believe it somehow relates to the hot/cold air cicuit via the flap in the factory air cleaner. It should be capped so not to allow unfiltered air to go through the engine. Looks to me like it would be a pia to make the kit accelerator diaphragm work, you might try NAPA again and see if you can get just the diaphragm they do stock some odd and end parts like that. As far as the accelerator pump adjusting goes, i have never heard of a "390 dial in vs. a "360 dial in" or the like. Depending on altitude, timing settings, and numerous other things you may need to adjust the accelerator pump. My suggestions, set timing approx. 1.5* more advanced than factory spec (possibly more at atlitudes above 4500 ft.) Then set your accelerator pump in the middle, take for a test drive, look for stumbling or hesitation on acceleration, if either of these are noticed, try moving the accelerator pump linkage up or down a hole, note whether condition improves or gets worse, adjust as necessary. Note: higher climates tend to need less fuel as there is less oxygen, therefore less throw on the Accelerator pump. If it is consistantly as cold as you mentioned though, you may want to put a slitghtly rich tune on the carb for easier starts and a less tempermental engine while shes warmin up.

 

As far as the "calibrations" go, my accelerator pump has multiple different configurations for where you can adjust the linkage which changes the rate / amount of fuel dumped when you step on it. According to the paperwork, mine was configured for a big block. I set it up for a 302 when I rebuilt it. Here is a picture.


Ignore the green arrow and look at the lower right. See where there are two holes for the accelerator pump linkage to hook into? There is also some adjustment on the other end that you cannot see. These variable connection points are what tweaks the carb from one engine calibration to another as far as the accelerator pump is concerned.

Definitely get the right kit for that accelerator pump. I was very happy with the kit I got from Autozone for $13, you might try them.

As far as the hose going nowhere, that is for your hot air choke. Fresh filtered air is supposed to be drawn from the there, down around the manifold, and back up to the choke housing where it helps to heat the choke spring. If you are not using the hot air choke you would need to cap this off as it is allowing unfiltered air past the filter. You will also need to cap off the hot air input on the choke housing because it is also allowing unfiltered air into your carb. A better solution though is to just fix the hot air choke. The electric portion alone will NOT work properly as it was not designed to. It is an electrically assisted hot air choke. Fixing the hot air part of the choke was one of the best things I have ever done for the driveability of my truck.

Since the factory parts of my hot air choke were gone, I made my own with copper tubing, here are some pictures.


Soft copper tubing is connected via the rubber vacuum hose to the port you were asking about. This is the tube on the left. This tube then goes down and wraps around the exhaust pipe a time or two down at the manifold. Wrap it as tightly as possible but be extremely careful not to kink the tubing. Then it comes back up and attaches to the choke housing via a flared end and a fitting. The blue arrows point to the hot air part of the choke and the red arrow points to the electric part.


Here is where the choke tube wraps around the pipe.

 

Thanks for the pictures. I'm curious: what tools were required to bend to copper tubing? Anything special, or did you do it just by hand strength and body heat? Did you have to take off the exhaust pipe to bend the tubing around the pipe?

Thanks -

Fish

 

Wow ya know, that right there is a handy dandy idea, nice work!

 

It is 1/8" soft copper and can very readily be bent by hand although it is extremely easy to kink it. My dad had these little spring like things that you can slide over a piece of tubing to bend it and help prevent kinks, I don't know what they are called. We were able to do it with the exhaust pipe in place.

 

Well, the carb is back on the engine and it's running, so that means I didn't F up anything so bad that it wouldn't start! I feel so...manly...having just rebuilt my carb successfully.

Vacuum gauge reads 18" Hg (at 4800') and the needle is steady, which leads me to believe that there are no major vacuum leaks anywhere on the engine. My neighbor has a dwell meter that he's going to let me borrow to set idle speed when he gets home.

Sometime this week, I'll be able to rig up the hot air choke similar to how you've got your rigged, Nathan. Thanks for the tip.

Fish

 

Good, glad to hear it. You might see if you can pick up this style of tubing bender, it will help you not kink it. http://www.ridgid.com/Tools/Spring-Tube-Benders

For what it's worth, it is a royal pain but well worth the effort when you're done.

And you would need some way to flare the end so it stays in place. I believe there are "choke stove kits" that may be easier if you can track one down.

 

Fabricated my own choke stove today with 1/4" soft copper tubing, nearly identical to how you did yours Nathan, except I laid the tubing alongside the exhaust pipe instead of wrapping it around. You're right in that it was a royal pain. It still seemed to work, but I'll be using an excellent write up by FMCx00 (user here on FTE) to adjust the choke and tune the carb tomorrow.

Thanks for the tips -

Fish