Starting new thread for same old problem.....

rustystud said:

I have a spare carburetor I can take pictures of as I tear it down to show you how to rebuild it.
Will that help you ?

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Howdy, Since I have no actual assembly dwg for that carb, perhaps you could be able to tell me?
The order of the gaskets between the top (horn?) of the carb and the main body? Mine has fiber / metal / fiber. But what keeps that botton fiber gasket from sagging down toward the float?
I believe ther is supposed to be a needle valve called "Pump Discharge Needle Valve" goes straight down into the carb body? I don't think this carb had one in it for the last 10 years or so? But the other two old carbs I have both had it. So I put one of them in this one?
But it has ran fine for 10 years or more??
I am not positive this float is set correct, but how could it have changed? I did nothing to the float or it's setting?
Thanks

When it’s sputtering are you getting black smoke? Maybe this is the carburetor flooding. Hard to detect this since you can’t see down the throat of the Holley.

I have not noticed any black smoke, except once when he was shifting gears. (we have a standard 5 speed manual transmission in this truck)
However there is wet black soot running down the outside of the stack now that it's raining?
So how could this problem be addressed? There are only the two idle screw adjustments on the carb???

OK. First off you need to determine if your ignition system is working properly. That means your points, condenser, cap and rotor, spark plugs and cables. Once they have been fully checked out, you then can go and check the fuel system.
No more jumping around. That gets you nowhere fast. You need to be methodical about this. Don't "assume" anything is OK until you check it out. Even if you just "replaced" it.
So, make a plan and go from there.

Yesterday I watched videos on how to check the condenser and coil with a volt meter. It is hard to check the coil to see if it is only bad when it's hot because it takes so long to take the cap off. So we ordered a new coil. The one in it checks out ok when cold.
Otherwise almost everything is new, the points, condenser, 6 new plugs. The wires are about 15 years old and I am going to check them today as best I can with the volt meter. ABout all I can check for is continuaty?
The original capacitor had a broken wire so I had an old one and replaced it with it. Would a bad capacitor effect the running? I was told they are only for radio static?
I have 24V to the coil and to the fuel pump.

Waiting on the new coil, pray that's the fix. Yesterday we checked each plug wire with a meter for continuaty and any shorts to the outside braided cover. All seemed fine
Bought a can of starting fluid and while running, sprayed all intake areas, the manifold and carb base, etc. No sign of any leaks.
My manual shows point gap should be .022. I have checked it a couple times and am confident I have that about right. However there is a local guy that was a pretty good mechanic at a Chevy garage of old and he says he never saw points that wide?
I just wonder if somehow this truck got out of time? Maybe the timing chain jumped a tooth or whatevrer.
I just walked out and hit the starter and it started right up and idles. But after a couple hundred yards it just sputters out? I can keep it running by working the throttle, but it will not go like that.

Go check the fuel inlet line to the carburetor. There is a fitting where the line goes in and on top of that is a wire screen that gets clogged up and causes exactly what you are describing. Remove that fitting and check the wire screen. Here is a picture of one I dealt with that was causing the same issue you are dealing with. I have started putting an inline fuel filter just before the carburetor to stop this from happening.



It sound's like you might have other issues/missing pieces in there as well so this might not fix all of your problems.

I am not sure I had that portion apart when I took the carb apart.
I am going out this very minute and check that. But we have always had an in-line filter just ahead of the carb. But who knows!? I gotta check it out.
Thanks

Well, thanks for the filter tip. But I just checked and my carb did not even have that filter in it, In fact I checked the other two parts carbs I have and they didn't either. I suppose that is why we always had that in-line filter just ahead of the carb.
I tried blowing in the line and it was near impossible. But I guess that should be closed if there was gas in the float bowl? I will look for a way to drain that without taking the carb apart?

I just went out in the total dark and started the truck. Sprayed a mist of water all over the plug wires and dist cap. Saw no sparks at all.
Same old thing, starts right up and idles fine. Try and go and within a couple hundred yards can't pull itself?

It sure presents as a fuel restriction or a breakdown of spark, but without actually hearing the engine it's hard to nail it .. Everyone has covered the possibilities .. Something will pop up sometime

Someone has suggested it may be getting too much fuel? Asked about black smoke? I just took these photos. You can see the wet soot sticking to the exhaust stack. In the second photo the engine is running at idle. There is never any smoke visable when it is running, but there is this soot like stuff at the stack?

You will see some soot normally. A carb flood is very distinctive, will be running fine then acts like you pull the choke.
Did you do the fuel delivery check into a bucket yet? Needs to have full flow for a least a half a gallon.

OK. Lets regroup here for a moment. You have replaced the points and condenser, checked the electrical system for spark leaks and are now checking the fuel system. You replaced the fuel filter and rebuilt the carburetor. When you rebuilt the carburetor did you replace the governor diaphragm and clean the unit ?
If the governor is malfunctioning it will cut your fuel off.
This Holley carburetor is a very sophisticated unit. It has over 10 metered orifices that I could count, and an extremely complicated air intake system for just a two-barrel carburetor. You need to follow the rebuild instructions carefully.

NDT said:

You will see some soot normally. A carb flood is very distinctive, will be running fine then acts like you pull the choke.
Did you do the fuel delivery check into a bucket yet? Needs to have full flow for a least a half a gallon.

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Gonna do the fuel test as soon as I get someone here to help.

Rusty, I am not very familiar with how carbs function. I actually did not "rebuild" the carb. I just took it partially apart looking for crud, or an obvious problem. I did not take the the governor apart at all.
I am not capable of actually rebuilding that carb.
Would you know of anyone that could do a god job rebuilding that for us? Perhaps you?
Once we get that new coil in it, and that doesn't fix it? Well, I am beat.
Thanks for your knowledge. I can replace parts, but to actually rebuild a carb, that's pretty much beyond me.

It's real nice to see everything on one thread instead of adding a new thread for each challenge. You're much easier to find all on one thread.

Solve the fuel pressure question with a regulator and gauge. If you didn't need one before it's odd it could be a problem unless there's a new restriction after the tank and before the carb. It's just another toy to help read and regulate the truck. I could dial pressure up to around 6 and eventually dial it back to 3.5 psi where the truck seemed happy.



I don't know much but I know it's not the timing chain. It's direct gear drive from crank to cam. Many timing gears have been aluminum so I guess it's conceivable a tooth could break but your symptoms don't sound timing related. .........



..........as I'm typing something else popped into the cranium. Maybe those mechanic brains can help us out here on timing advance and if the governor lines around the back of the engine would cause his symptoms.

After pulling the floor pan, many of the trucks had damaged lines around the back of the engine. It appears the floor pan can rub through over time. After going through and eliminating other possibilities, checking sensitive rubber for cracks and leaks is always a good plan.

It's an easy job to pull the floor pan and get a look at the 2 lines from the carb, around the back of the engine, to the distributor. Most are metal then adapt into a rubber hose to flex into the distributor.

Many of those rubber lines disintegrated when we were pulling distributors out of 'take-out' engines. The connection on one line is a little tough to get at and you typically need two small wrenches in there to crack the lines. It's easier with the oil bath monster filter out of the way but those lines can be inspected with the floor pan off.



It's just one other thing that can be checked fairly easy, it's a one man job and gives a guy a chance to clean things up so they stay cool.

Compression checks can also be a one man job that gives you a health status on the squeeze part of the suck, bang and blow engine sequence.



I was parked beside a pretty rare jeep one time that had some real nice paint and canvas on it. The NEW rule was never to park on the exhaust side of a deuce because they may spit black soot on start up. We found out that windex helps to remove soot off paint and canvas.

It's good to find that out early because one never knows when a Sentimental Journey might show up and we do not want to get soot on our bomber.

Thanks to all. Just waiting on that new coil before jumping in again.
Where do you get that gauge and presure regulator?

Brad said:

Thanks to all. Just waiting on that new coil before jumping in again.
Where do you get that gauge and presure regulator?

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I drove down the street to get mine. Any automotive store should carry them. I just did a search for"fuel pressure regulator 3.5psi" to see what's online and found a bunch cheaper than what I paid. Summit has some $200.00 regulators so looks like you can spend somewhere between $31.00 and 200.

This may have been tried, but go for a run with the gas cap off.

Sounds to me like whatever is used to admit air into the tank as fuel is drawn off is causing a vacuum the pump can't overcome.

Just a thought...