yesterday I got about 500 feet from my house in my 1978 L82 4 speed and my car suddenly died. Like it ran out of gas. Had half a tank. I put some gas in the tank if for no other reason than to rule out a bad gas gauge. Starter cranks but no go. I poured a bit of gas down the carb throat, and it started right up and ran for a few seconds consuming whatever gas I manually added. To get the car home I did this several times letting out the clutch traveling about 20 to 50 feet and finally got home. Not the best but all I knew how to do it to get it home.

But I think this tells me that I have air and ignition, just no fuel from the fuel pump. Looking down the throats of the carb and moving the accelerator I see no gas coming into the venturis.

I removed the fuel pipe to the carb and ran the starter. The fuel pump did in fact pump fuel. Not able to measure flow or pressure but it seemed like a lot of fuel for the short time on just the starter. Indicates to me that I have fuel at the carb.

I am just leaving work now and have a few large wrenches to open up the fuel filter to look for a plugged filter.

My internet mechanic diagnosis is there is something wrong between the fuel inlet on the carb and the venturis. Plugged filter, bad plunger, clogged jets.

The numbers on the carb are 17058228 which my research tells me is a 1978 Chevy carb, federal emissions and manual transmission. The other numbers are 1178 BJM. I am not sure what the BJM means.

Any comments on my diagnosis so far and other suggestions are appreciated. I know more about women than I do about carbs. Assuming I do not find a plugged filter, I am thinking that this carb may need a rebuild.

Is it a rebuildable carb or is it a frankencarb? This carb has been on my car for about 500 miles. No need to bring up the angst I have with a mechanic who removed my old carb and put this one on. Pissed me off.

Pictures of my carb.

 

Carb looks like a nice, original, unmolested carb in rebuildable condition. If you have fuel flow and pressure at the inlet, but no fuel getting into the carb, you either have a plugged fuel filter (mosty likely) or a float that has swollen up and is jammed in the "up"position. Both issues can be easily fixed in minutes.

Lars

 

That makes me feel good to find out the carb is good and rebuildable. I am finishing up rebuild of rear end and will be looking at the soundness of the engine in my next project.

i did open up the filter nut this afternoon. The spring and plunger of the check valve were loose and out of place. Fell out of filter when I pulled it out. Put in a new filter and got it started and running. Did not test drive and not really sure I fixed it or not. We will see.

Thanks for your valuable input.

 

OK , have it running. But I have a gas leak on the fuel inlet. It is between the large inlet fitting and the carb itself - the inlet where the filter is located. I did not see any gasket in this location should there be one? If so do I use a copper crush gasket from the hardware store, A rubber O Ring? or is there a special gasket I need to order.

Thanks for any help as always

Ok back home and I removed the fitting for a better look. There is/was a nylon plastic O Ring. But it is all buggered up. It was loose inside the housing.

Where can I get these as I am guessing these might not be a hardware store variety?

Jim

 

Yes, it is a specialty gasket specifically for the Q-Jet inlet fitting. You can get the seal from any good auto parts store, and be aware that there are 2 different gaskets: One for the 7/8-20 inlet and one for the 1"-20 fitting.

Advance auto parts also sells Dorman part number 55143 which contains the nylon gasket.