Fiat 126 bis

The car will take about 20 minutes to start, then will run for a few minutes then putter out. Once I poured a little gas in the carberator and it choked a few times then started. But didn’t last too long. I know nothing about engines, but it seems like something is clogged in the fuel line. Is there an easy way to check this out?

You don’t mention the year of manufacture of this Fiat but you mention ‘carburator’ so I am assuming you have a mechanical fuel pump. It sounds like the fuel pump is failing, although a badly clogged fuel filter, clogged fuel pickup screen in the tank, a clogged fuel line, a collapsed flexible hose, or an air leak into the fuel line leading to the pump could be possible. If you want to check the fuel pump pressure, put a pressure gauge on the carburator line, crank the engine, and see if you get the required pressure (>5 psi). If that is okey, put the carburator line into a can or jar, crank the engine and see if you get the specified amount of fuel (~1 pint in 30 seconds). If that is okey, reconnect the carburator line, disconnect the line from the tank to the fuel pump, put the fuel pump test gauge on the inlet side of the pump, crank the engine and see if you get the specified vacuum, (>15 inches of mercury). If that is okey, place a can or jar to catch the fuel from the tank line, pressurize the tank lightly <2 psi through the filler neck, and see if you are getting flow. If not go to the other side of the fuel filter and try again. If all this is okey, reconnect everything, pressurize the tank as before <2psi, and see if you can find any fuel leaks. Fuel leaks under pressure will be air leaks under suction. That should get you closer to narrowing down the problem. In my experience, the problem is usually the mechanical fuel pump or filter in that order.

Hope that helps. Reply with any questions.

The previous post is right on target. I had a similar problem with my 1978 Oldsmobile Cutlass 4-4-2. I replaced the fuel pump, but that didn’t help. An old time mechanic found that a section of neoprene fuel line at the gasoline tank had deteriorated and the car was sucking air. Replacement of the line solved the problem. I was glad that I didn’t tear into the carburetor. My brother was having the same problem with his 1969 Buick Gran Sport and when I told him how I fixed my Oldsmobile he found the same problem on his Buick. It is possible that the ethanol in many of today’s gasolines has a adverse effect on fuel lines.