Fuel System: Will not start

[MrBulldops]

(picks up from: http://forum.studebakerdriversclub.c...33#post1081333)

I'm at my wits end trying to get this car to run correctly...

So NOW, my hot starting, high-idle issue is corrected. In its place, I can now not start my car cold without 25 minutes to spare. If I set the choke to the manual--on the center notch--the car makes what I can only describe as a "revving starter" sound; like it sorta vaguely ignites every couple of cycles, but not enough to kick over. If I set the choke one notch rich, the starter just runs and runs. If I set the choke lean, the result is the same as on the center notch, unless I set it so lean that it's off the scale, and then it will fire up enough to disengage the starter and immediately die. One pump, fifteen pumps, and everywhere in-between yeilds the same result: nothing. Eventually, after a lot of grinding away at my starter and unloading and fiddling with the choke settings, I can get it to run enough--extremely roughly, by the way--that if I keep the accelerator floored, the idle will clear up and the engine will run. Once it's warm enough to run on its own, it runs like a top; smooth, pulls well, restarts perfectly fine. But once it cools off, I'm back to square one.

Now, when I replaced my manifold gasket, I re-rebuilt the carb. What I mean to say is that I took all the brand new components of the rebuild and inspected and cleaned them, put them carefully back together, step by step, according to the shop manual, and made every adjustment, in order, precisely according to the book. I triple-checked every single one with feeler gauges and verified free movement of each and every moving part before I put that thing back on my car. I cannot stress this enough: the carb is set EXACTLY per the Studebaker shop manual... Except the choke, which currently has no correct setting that I can determine.

In case you missed the previous thread, I've replace the following:

Complete carb rebuild
Manifold gasket
Exhaust flange gasket
Battery
Spark plugs and cables
Coil
Condenser

Thoughts?

[Commander Eddie]

New condenser?

[MrBulldops]

New condenser?

In the distributor

[63 R2 Hawk]

Most of the new ignition parts come from overseas manufacturers who have minimal quality control and make generic parts to fit a wide variety of vintage cars, so just because something is new doesn't mean it's going to work as good as the original OEM spec'd part, or even work at all. New repro condensers are often bad out of the box. You might try to find an "old school" repair shop that has the equipment and knowledge to test components like condensers, coils, distributors etc. Something to check (assuming it's a 12 volt system), are you getting a full 12 volts to the coil when the starter is engaged and does it switch to the lower ballasted voltage in the "run" position? Is coil polarity correct?

[altair]

Try this test, solder up a light bulb with alligator clips and attach it to the coil and crank the starter, the light bulb should not go out while cranking, if it goes out or very dim there is a ground problem with the starter.

[Buzzard]

Any chance you have had moisture (condensation) gravitate into the fuel tank? I just had a similar problem in my son's boat (454 CID FI Gas). H2O removed and runs like a top. Just a thought....
Bill

[TWChamp]

Any chance you have had moisture (condensation) gravitate into the fuel tank? I just had a similar problem in my son's boat (454 CID FI Gas). H2O removed and runs like a top. Just a thought....
Bill

I had the same thought. If you are using the 10% crap gas, then it attracts moisture and has a short shelf life. It made the valves stick on my 49 Chevy truck and bent the push rods 2 different times. Now I only buy the gas without the ethanol crap, and I add 4 ounces of Marvel Mystery Oil to each 10 gallons, and have no problems.

[gordr]

Can I suggest that you have another club member who has mechanical skills take a look at it? Sometimes another set of eyes/ears will see/hear things that you don't. I'm back in Alberta; otherwise I'd happily volunteer.

Will it start if you prime the carb?

[PackardV8]

Quite a gremlin you're trying to exorcise. First it starts but won't run; then it runs but won't start cold.

Will it start if you prime the carb?

One pump, fifteen pumps, and everywhere in-between yeilds the same result: nothing. Eventually, after a lot of grinding away at my starter and unloading and fiddling with the choke settings, I can get it to run enough--extremely roughly, by the way--that if I keep the accelerator floored,

We're assuming the accelerator pump is producing a full squirt with each pump?

jack vines

[MrBulldops]

Can I suggest that you have another club member who has mechanical skills take a look at it? Sometimes another set of eyes/ears will see/hear things that you don't. I'm back in Alberta; otherwise I'd happily volunteer.

Will it start if you prime the carb?

If by prime you mean pump the accelerator, no. It will sound more apt to at first try, but floods out (I can smell raw fuel under the hood). I've tried one, two, three pumps, no pumps before turning over. I've tried flooring the accelerator to unload the choke, I've tried every choke notch.

I don't have anywhere local that I know of to get non-alcoholic gas, but I do put 8 ounces of Marvel Mystery Oil in when I fill up. It's a non pressurized system with a two way vented cap, so it's possible I've got moisture in my tank, but I live in AZ and it hasn't rained recently, so I doubt it's that. I also drive it every day, so the fuel is used up regularly.

Could it be the idle mixture screw is set too rich? I bottom it out and back off two turns to start, then, when it's up to operating temp, set the idle speed screw and smooth out the idle with the mixture screw. Same procedure I use on Amals. Should I be increasing the idle speed to lean the mixture to a point of equilibrium? Basically, turn the screw clockwise to the point of stumbling and increase the speed screw to compensate. As I understand, clockwise is lean, counter is rich.

[MrBulldops]

Quite a gremlin you're trying to exorcise. First it starts but won't run; then it runs but won't start cold.


We're assuming the accelerator pump is producing a full squirt with each pump?

jack vines

It is. I verified visually, and it is a new pump.

[Ron Strasser]

McBulldops;
To me it sounds like the engine is flooded with fuel. Try this. With the air cleaner off stick something into the carburetor.
What happens?
If the engine tries to start after clearing out the excess fuel; the question becomes; where is the excess fuel coming from.
You might also try starting the engine with the fuel line to the fuel pump disconnected.
Ron

[jackb]

read #8 & #12 ...again

[MrBulldops]

If i try to turn the engine over normally, with the choke partially engaged, I can see droplets of fuel coming from the center port of the air horn, and if I open the throttle, there is visible liquid fuel in the manifold. So, I decided that the idle mixture would be a good place to start: I bottomed the mixture screw out, and backed off two turns--by the way, when I say 'two turns', I mean one 360 degree rotation of the screw--and managed to get the engine started after it sucked all the liquid out. After running it up to operating temp and verifying the choke was disengaged, I turned the screw in roughly half a turn and smoothed out the throttle with the speed screw, then made a slight tweak counter clockwise on the mixture screw to balance it out; maybe an 8th of a turn or less. So, that means I'm roughly 1-1/2 turns (270 degrees) out from the seat on the mixture screw. I also set the choke to the second to last notch (when it was cold) on the lean side; roughly where the spring just starts to engage the valve. I'll update you in the morning as to whether it starts cold or not.

[gordr]

One 360 degree rotation of the mixture screw = one turn. No way that "one turn" = 180 degrees. Normal setting for mixture screws is typically 1 1/2 turns, which is 540 degrees, or 3 pi radians in metric.

But it sounds to me like there might be a problem with the carb float or the float valve, making it run excessively rich. I once saw a '50 Champion, with the Carter WE carb, in which the float valve body had come loose inside the carb, and unscrewed several full turns, forcing the float right to the bottom of the bowl. Enough fuel seeped in around the threaded body of the valve to make it flood out at idle, but put it in Drive and go, and it would starve out and stall. Your AS carb isn't built the same way, so that particular problem cannot occur, but floats can sink, or their pivots get in a bind, or a piece of debris, like a shred of rubber from a flex hose, can become lodged in the valve seat, and cause a similar condition.

Because modern fuel is less dense than what was sold when our cars were new, the floats do not float quite as high in the bowl as they used to do, so the fuel level rises higher before the float valve gets closed. For that reason, I like to set the float level about 1/16" lower than the factory figure. Seems to work better that way.

Oh, priming. By "priming", I mean squirting a shot of gasoline into the carb air horn from a squirt bottle. A very useful trick when trying to start an engine that has had all its fuel evaporate from the carb.