Let me start off saying that all of the posts on this site about re-built carbs from places like Advance Auto are 100% correct!

I have been fighting a rough idle, bog and a few other problems with this carb since I bought it. Last night I had had enough. I pulled the carb off and started from scratch.

First things first the floats were close to a 1/2" low, the rebuild sheet I have says they should be about 3/32, I got them adjusted close. The Accelerator pump rod was way off also, got it close.

After putting the carb back together there was a huge difference in the way the car ran. My question is this. Eventhough it ran much better, there is still some hesitation while accelerating and the idle is still not completely smooth. Should I think about some different jets and if so should NAPA carry those?

Any help would be appreciated

I've been told the jets for a Holley 4bbl will work...

Give it a try. Unfortunately the idle may never get better -- we've discussed it on the site recently. The idle passages have fixed (pressed in) bleeds and are sealed (with lead ball plugs). Once they get stuff built up in them, it's damn near impossible to fix without heroic effort.

Once I went back through mine, it's working better. Still too rich though; but, I'm getting 16mpg. As long as it maintains that for now, I'm going to leave it alone. There's a 2bbl upgrade with a new carb in my future...

_________________
My truck is a Frankenstein creation
Built from the dead carcasses of others
And brought BACK TO LIFE!

Before I would recalibrate the carb, I would insure that the other componets that affect this are in working order. Vacuum advance working? Initial distributor timing? Advance timing? Vacuum leaks? Valve lash adjustment? Food for thought....

Thanks for the advice! The distributor is a NAPA re-built that has only been in the car about a month, I would assume that it is working correctly. I had a guy adjust the valves about a year ago, however I have never checked this myself, thought about it but was not sure exactly how to do it.
I don't have a problem getting the motor to TDC so I can check the no.1 cyl. but how can you be sure that you have the others in the right position before you adjust them? I would like to check this out, I'm not sure if they are set correctly or not.

Second about vacuum leaks I need to check that out as well, my only question about that is that I have the vacuum amplifier on my engine and the vacuum lines that run to it are made into this special thing that attaches to the Vac Amp. if there is a leak here how can you fix that? is this a part that can be bought?

Thanks

Thanks, I forget to mention these things; because, I assumed they would have already ruled them out. I forget not everyone is in my head (although there are more than one of us in here...)
You're talking about the rubber boot with hard plastic vacuum lines coming from it? The boot / connector attaches to the amplifier, right? Well, the hard tubing is available from most autoparts stores.

If the vacuum tubing is damaged, the tubing should (with some effort) pull out of said rubber boot and you should be able to push new tubing into it. You can use RTV to seal the tubing to the boot if necessary -- just be careful not to block the tube.

If the boot is leaking or doesn't fit tightly on the amplifier, the dealership might have them. Most likely your going to a junkyard --or-- I have had some success replacing these using soft rubber vacuum hose whose ID is small enough to fit the OD of the hard line snuggly and still fit over the nipple on the valve, amplifier, etc. Just be careful not to get the hoses mixed up.

_________________
My truck is a Frankenstein creation
Built from the dead carcasses of others
And brought BACK TO LIFE!

Whenever I hear that someone got a rebuilt (you fill in the blank) I shudder. Having worked at a parts store (NAPA) for several years I have seen some really crappy rebuilt (you fill in the blank). Not saying that they are ALL bad, but the ratio of 'good' to 'bad' was about 3 to 1. (This was mostly carbs.) I would double check the distributor to make sure. (Hint: the vacumm advance unit is probably adjustable. All you need is a very small allen wrench. Remove the hose and insert wrench and you can "dial" it in through trial and error.)
Valve lash adjustment is throughly covered in the 'articles' section.

Whoops!! The article on valve adjustment is at www.earlycuda.org in THEIR article section. To many sites to keep track of.

I have a 1945 in my 1980 Aspen. It gets about 25-26 mpg on the highway and does run really well all-around. You can get this carb to work and it's no harder, really, than any other carb. Yes, standard Holley jets fit. No, the idle feed restriction on this carb is readily accessible with the top cover off. It is the diagonal passage that runs down from the top cover gasket on the passenger's side surface to the idle mixture screw/idle transfer slot. You can identify it by spraying carb cleaner into this 'hole'. If you know how to dial-in this restriction, tuning here is easy. Cleaning is easy as well. The power valve channel restriction is sealed with lead shot. To gain access, you have to drill through the lead. Once you do this, you can increase the restriction to whatever you need. Sealing the channel must be done by heating the carb body with a torch and resealing with silver solder. So just about everything on the 1945 can be tuned. With the top cover off, you also have access to the accelerator pump shooter restriction.

Assuming everything else is OK with your car and the problem really is the carb, then jets should come later. First, what happens when you turn the idle mixture screw? Turning the screw in, will the engine begin to run rough? Does backing it out change anything?

You should realize that all the carb's specifications mentioned above change from year-to-year, and model-to-model. It is rare that you will be able to buy a carb and have it work perfectly right out of the box. Rebuilders assemble a carb from a mass of hundreds of disassembled cores and simply throw things together. It is hardly ever or purely by chance that you get close to what even should be on you car.

Mitch

The 16mpg I quoted was around town in a D-100 truck. That's not unreasonable (considering my ESC isn't working and I'm running a fixed 12*BTDC timing)

I tuned the idle mixture using the vacuum method. Hook up a vacuum gauge, set the idle speed, adjust the mixture for peak vacuum, reset the speed, re-adjust the mixture for peak vacuum, rinse, repeat.

I did identify and clean the idle air bleed and the main air bleed on my carb. The passages are as clean as I can get them, without removing the plugs. <---that's where I start referring to it as "Heroic effort" Not that I'm opposed to doing this; it's just a real pain. When I last rebuilt my carb, It was raining and I was sitting on the front porch of my apartment doing the work. If I had a garage and a drill press I might have removed them. I don't believe they bother in the "factory rebuilds" either. This may be one source of problems with them; and the source of the mystery idle problem if it doesn't get better when everything's properly adjusted.

We had a discussion recently where DD, for example, said he was finding 1in3 or 1in2 were bad because he suspected the sealed passages were plugged.

Sadly, This is EXACTLY what Holley does (admits to it) in their reman factory. Dissasemble, clean, put the parts in bins, build carb(s) from parts in bins as needed.

_________________
My truck is a Frankenstein creation
Built from the dead carcasses of others
And brought BACK TO LIFE!