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Thought I'd fix my 1945 carb and ruined it instead!
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Author:  daniel_depetro [ Sun Sep 20, 2009 9:22 am ]
Post subject:  Thought I'd fix my 1945 carb and ruined it instead!
I got my 8.25" rear installed and the gears are making noise. Dang it! Oh, well, I'll get it sorted out a little better at a later date and just will have to quit driving the car for a bit until I feel like messing with it again.
It was running like crap anyways.
So I decided I would try to tackle why the car is such a pig. It has run crappy since I bought it, but I have just been dealing with it up to this point.
It always started right up, but wouldn't idle until it started to warm up. Once warmed up it ran good, but didn't have any power (even less then a "normal" slant I believe).
The carburetor is a Holley rebuld and still looked fairly "new". Even the sticker was easily readable.
My dad wanted to take it apart and clean it up and see if that worked. I decided I would just pay the $18.00 for a complete rebuild kit and replace whatever was in there as we went.
Got everything apart and there was a fair amount of crud on the bottom of the where the float is and such so we cleaned it all up very nice.
We used all new gaskets & seals (matched them up with the gaskets that were in the carburetor) & jets (was a #58 and I drilled it out with a .062" drill bit) and put it all back together. We cleaned up all the linkages for the fast idle and such as well. The pivot points were greased up as well.
I though for sure my car was going to run like never before. It did but not in a positive way.
It starts and idles awesome. Nice and smooth, a 100% improvement.
The problem arises as soon as I touch the gas. The car runs out of fuel. You can hear the carb sucking in nothing but air (like when you are out of gas). This happens at anything over 5% throttle. If you just rest your foot on the gas pedal 1-5% it runs awesome! Almost like only the accelerator pump is working. Like the carb itself isn't pulling any fuel or something.

The car has ~6.5 psi of fuel pressure at the carburetor inlet.

I did the fuel line mod and eliminated all the emissions stuff.
All the vacuum lines are new and I hosed clamped them. I double checked for any vacuum leaks and came up empty.

I had my dad squirt some parts cleaner in the carburetor when I hit the gas and the engine rev'd up instantly and sounds healthy!
I wish this thing would just run correctly!!!! UGH!

I'll probably just scrap the one barrel and install my super six set-up, but I wanted to run the one barrel until I got my AussieSpeed Hurricane 2-bbl. intake so I wasn't doing that intake job twice.
Author:  Aggressive Ted [ Sun Sep 20, 2009 9:48 am ]
Post subject: 
Quote:
I had my dad squirt some parts cleaner in the carburetor when I hit the gas and the engine rev'd up instantly and sounds healthy!
I wish this thing would just run correctly!!!! UGH!
With the engine off, looking down the throat, pump the gas a few times.......tell us what you see.

How healthy is the pump shot?

This carb acts like the accelerator pump is not working very well and maybe clogged. When you said your dad sprayed a pump shot in the carb while it was running and it took off tells me the accelerator pump circuit is the culprit. Your almost there, don't give up now. :)
Author:  coconuteater64 [ Sun Sep 20, 2009 10:17 am ]
Post subject: 
You didn't ruin that carb. Holley did that when they made the thing!

Others will disagree. But I had one on my truck, and it was the absolute worst carburetor I have ever had! I rebuilt it twice, no no avail. Even a Holley 1920 straight out of the junkyard with no rebuild was an improvement!

Proceed with the super six conversion. You will not be disappointed in the result!
Author:  daniel_depetro [ Sun Sep 20, 2009 11:02 am ]
Post subject: 
Quote:
With the engine off, looking down the throat, pump the gas a few times.......tell us what you see.

How healthy is the pump shot?

This carb acts like the accelerator pump is not working very well and maybe clogged. When you said your dad sprayed a pump shot in the carb while it was running and it took off tells me the accelerator pump circuit is the culprit. Your almost there, don't give up now. :)
It seems to have a pretty healthy squirt of initial fuel.
I (and my dad and his buddy) watched it a few times the other day.

I figured the pump shot was the only thing working?!?
Then again I know nothing about this stuff.
From 5-100% throttle there is nothing...
One more thing I noticed... If I keep tapping (more like fluttering/feathering) the throttle from "closed/off/idle" to the 5% it will rev up throughout the entire RPM range. This is why I figured the pump shot was the only thing working.




Quote:
You didn't ruin that carb. Holley did that when they made the thing!
I have heard that these carburetors didn't survive the part store reman process very well, however I was hoping since Holley sold this as a reman unit it would be better.

Quote:
Proceed with the super six conversion. You will not be disappointed in the result!
It will be three weeks before I will have the money to get the Remflex gaskets and a rebuild kit for the 2-bbl. carb I have.
Not too mention by the time it got it there may be snow on the ground! :shock:
Currently my Duster is (was) my daily driver... I should have left the 7-1/4" rear with 2.76:1 gears & well worn drum brakes (that didn't work at all) and just suffered with the carb as it was. :oops:
Author:  Aggressive Ted [ Sun Sep 20, 2009 11:16 am ]
Post subject: 
On the 1945 you need a real healthy shot timed right or it just sucks air.....as you described. I have three 1945's and they all suffered from the same problem, however you can get better accelerator pump pistons and put it on the more aggressive setting. Some of the thin rubber pump pistons seem to damage easily when reassembling the carb. You may have torn yours. Did you take out the power valve diaphram and install a new one? The old one could be ruptured.

The carb is set up to run super lean, not for tire spinning performance.

My 1920 Holly Economaster has a healthy enough pump shot and power valve to spin both tires.
Author:  daniel_depetro [ Sun Sep 20, 2009 11:50 am ]
Post subject: 
Good/interesting information. There is a good probability that's what is happeneing then.
How could I "fix" it?
Where would I find of of the better pistons?
Can I adjust the installed piston for a bigger shot?
The kit came with two new powervalves, I installed one of those.

I don't think anything was damaged, however it's possible.
We are pretty meticulous with our work.

Also the kit I used came with two of everything.
The instructions never specified when to use Part A or Part B so I just installed the parts that looked closest to what was removed.
Author:  Aggressive Ted [ Sun Sep 20, 2009 12:03 pm ]
Post subject: 
Try a Walker pump diaphragm. However if you think it's ok, try a more aggressive slot for a long sustained pump shot (the furthest one out and the longest). Then take all the slop out by bending the looped wire so it engages immediately when you crack the throttle.

Did you use the power valve with the biggest holes?
Author:  daniel_depetro [ Sun Sep 20, 2009 12:06 pm ]
Post subject: 
Quote:
if you think it's ok, try a more aggressive slot for a long sustained pump shot (the furthest one out and the longest). Then take all the slop out by bending the looped wire so it engages immediately when you crack the throttle.
I'll try this first.
If this doesn't work I'll try one of the Walker pumps.



Quote:
Did you use the power valve with the biggest holes?
I don't really remember, I'll have to look.
If I didn't the one with the biggest holes is the one I should use?
Author:  SlantSixDan [ Sun Sep 20, 2009 2:56 pm ]
Post subject: 
Carburetor operation and repair manuals (and some training movies) are posted here for free download. "Remanufactured" carburetors are generally trash no matter whose name is on them.

(Send me a PM if you want a new carb…)
Author:  dennisd4o [ Sun Sep 20, 2009 5:08 pm ]
Post subject: 
If you can't get it to run above idle no matter how slowly you open the throttle the accelerator pump is not the problem. Your main metering circuit is blocked.
If it only stumbles on the transition ignore this advice.
Author:  volaredon [ Sun Sep 20, 2009 6:54 pm ]
Post subject: 
Ihear alot of mention of "walker" carb components and rebuild kits; What handy dandy auto parts chain sells this brand???? Most around here are GP Sorensen.
Author:  daniel_depetro [ Sun Sep 20, 2009 7:12 pm ]
Post subject: 
Quote:
Most around here are GP Sorensen.
That's what I used from Advance Auto Parts.
I don't think it is a problem with a part from the rebuild kit.
Author:  coconuteater64 [ Mon Sep 21, 2009 10:06 am ]
Post subject: 
I agree with Dan about reman carbs. I had one that had a HOLE in the float!

as for yours, you might want to check to see if the throttle shaft has wobbled out the carb base. That was the culprit with my 1945 that made it run horribly. the only solution is to have the thing rebushed, or toss that carb. A wobbly shaft allows air to suck in, messing up the idle circuit and generally causing you to pull your hair out.
Author:  oldblue [ Mon Sep 21, 2009 10:18 am ]
Post subject: 
O'reilly's carries walker parts.The kit I bought is made in usa.
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