VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 1941 SD getting fuel to the carb

Wanted some insights into what I'm seeing on my 1941 SD as I work to get it back on the road...so far, all the other projects have gone well.

This weekend: got the refurb'd radiator back in, new fuel pump in, new fuel line from outlet side of pump up to carb installed, with new fuel filter (NAPA Pro-Select basic plastic in-line fuel filter ), new radiator hoses, belt, new 6-volt battery fully charged up. Using feeler gauge and instructions from this site, I followed the sequence on setting the intake and exhaust valve settings (.006 for intake, .013 for exhaust). All the plugs are clean and gaped correctly. I didn't do anything with timing etc. and I labeled all my spark plug wires and put them back on the right plugs. All new oil and fluids are in. I have hand rotated everything to make sure all was free, oil and Marvel Mystery Oil had all worked its way through etc...should be ready to go and fire it up! (its been sitting for more than 25+ years...engine rebuilt in the late '70's and has less than 50 miles on it).

So, rather than putting in the refurbished gas tank and the rear line and filling it up, I decide to just check and see if I could fire it up by putting a 5' flexible fuel hose onto intake of the fuel pump and putting the hose end into a small gas can I keep for emergencies...gas is fresh. Shot a bit of starter fluid into the carb just for grins...I wasn't expecting it to fire up, but I was surprised when I started it that no/very little gas was lifted to the fuel filter up by the carburetor! Overall the engine turns over just fine (didn't fire), but no matter what my daughter and I did, we couldn't get gas up to filling up that plastic bowl on the filter...being horizontal, I was expecting fuel to be pumped up there and fill that bowl, if not to the top, almost to the top...thoughts? When I installed the new fuel pump, I could feel and had to press the actuator arm against the cam shaft as I bolted it in...other reasons I might not be getting fuel up there? I have not checked anything to see if I'm getting any spark, or the timing is off, but I would have expected fuel, even with my rigged up fuel hose from a gas can to be lifted up...more priming of the pump? We tried a number of things, but nothing just dribs and drabs coming up there.

Thanks for any insights.

Remove the fitting on the fuel pump on the line to the carbureator. With your helper turning over the engine place your thumb on the exit on the fuel pump and feel for any pressure. I suspect you will not feel any. Remove the fuel pump. Open it up, very carefully capture the springs on each valve. Remove the unit (Valve) and carefully clean each disc, the disc seat, inspect the springs for rust, and then reassemble. Reinstall the fuel pump and start the engine.

Some laws exist that I am not knowdegable, about the amount of fuel in the fuel filter. If you have any at all, pull the tab on a cool can from the shop refrigerator.

Enjoy your drink, I'm going to bed.

Thanks for the quick response...the fuel pump is brand new, straight from the box and sealed bag...do you think it still might be inside? I will try and see if I am getting pressure from the fitting between fuel pump and carb. All the fuel lines are new too as are the fittings. I will check the pressure though...if no pressure still an issue with pump.

Do these new aftermarket pumps need any priming?

I agree with Ray that you need to check the fuel pump. I had one of the check valves fall out of the recess in the housing on a new fuel pump I bought from NAPA.

The hard lesson I continue to learn is that "New" does not equal "Good".

You might try to start the car with the fuel filter out of the system. I do not know the flow characteristics of that particular filter. It could be creating more resistance than the pump can handle.

I have a Fram G2 fuel filter between the tank and the pump. It is sized for 5/16" hose so it has plenty of flow capacity.

Ray, Rusty...thanks so much for the responses and wisdom...I'll break it down by component, starting with the fuel pump to see what is going on there. The fuel pump is from NAPA too (now ya got me worried!). I may come back to you with pictures etc. once I crack it open, so hopefully it will be obvious what I'm looking for...venturing into new territory for my mechanical abilities. I'll double check the fuel filter input/output size. The rubber hose I'm using to connect it is plenty big (fits the metal fuel line well, but I believe the plastic input fitting into the filter is 3/8" (in and out), so perhaps I need to up-size that...I'll double check all of this piece by piece and keep you posted.

Someone has tag line "why do I spend more time under my car, than driving it?"...so true, but still enjoyable to work on these cars, particularly with my daughter!

Will keep you posted on what we find and we'll get it up and running yet!


NEW INFO: Just checked my inline fuel filter box: NAPA Gold Filter, part number 3002 and it is 5/16" input and output, so I'll assume that is enough flow capacity. I mounted it where the old one was, up near the carburetor after the fuel line makes that 90 degree bend coming around the rocker arm cover. For now, I'll check that off the list and focus on the pump later this evening...hotter than the devil here in Chicago today.

I agree that your fuel filter should not be an issue from a capacity perspective.

Please consider this a favor to humor an old man. I know this sounds crazy but try to blow air or pull vacuum through the fuel filter to confirm it was made okay. I have seen a few cases when the plastic did not flow properly in the molding process and either the inlet or outlet was blocked.

Ray/Rusty,

Here's the update...I did a better job getting the input gas line setup from my kludged setup from yesterday...better tank, better connections, a priming pump to put more gas initially into the fuel pump...turned the motor over and the fuel filter filled up so that the filter is soaked and appears to flow to the other side. I need to check it out more, but it appears that fuel is lifted up to flow into the carburetor. Is there a way to look into the carburetor and see if fuel is flowing in? Take the top off and look? I need to research this, but I think the pump is ok.

The engine turns over well, but it hasn't fired. I need to explore this area as to whether I'm getting any type of spark/timing...this will be new territory for me. I'll probably need to open a new thread on this topic after I do some searching and reading of the manual...any pointers always welcomed.

I appreciate the tips and help...I'll keep working on this and believe it will get fired up soon. I recall that many years ago when it ran, it got badly out of timing and stopped running...this is the area I need to learn more about.

thanks