'77 Carb issues

[Rupesy]

I am a new owner of '77 spider and I am having issues with the carb. It starts and runs fine until it gets warm and then I have trouble keeping it running. I pulled the air cleaner today to have a look and it looks like gas is leaking into the carb. The secondary carb fills up with gas while running. If I shut off the car, both fill up with gas I guess until the pressure is relieved. Is this something that can be fixed with a rebuild kit, or is it something more simple than that? Seems like it is float related. Looks like I have the ADFA carb from the "Artigue" manual.

Thanks......also, anywhere I can get some pdf manuals, etc??

(I am an experience mechanic, just don't know much about Fiats yet!)

[So Cal Mark]

you either need a new float or needle and seat; or both. Most likely the float is bad

[brunorahl]

Did the previous owner install an electric fuel pump? A webber carburetor is only designed to function on 3.8psi and many universal aftermarket pumps put out more. Too much pressure will force past your needle and seat. You could also build too much pressure from the return line and fuel tank vent system being plugged. You can check your return line by taking it off from the carburetor and blowing compressed air back into the tank.

[manoa matt]

Remove the 6 screws on the top of the carb and lift the top off. Check that the needle seat housing is fully screwed into the top housing. A friend had ongoing problems where the needle seat housing would come unscrewed allowing gas past the threads filling the float bowl spilling and spitting out the air corrector jets.

[brunorahl]

Excellent thought Matt. It could be the aluminum washer that the seat uses as a seal / crush washer. If it was played with, the washer may need to be replaced. They aren't ment to be crushed multiple times.

[manoa matt]

We tried an aluminum washer, copper washer, and a fiber washer, not sure which one finally worked, but it took several tries and would work itself loose every few weeks or so, it was also a daily driver.

[Rupesy]

Thanks for the tips so far, I will give them all a try and report back.....

[Rupesy]

finally found a few minutes to go after the carb issue (a year and a half later LOL). Looks like I have a 32 adfa. Anyway, it turns out that the PO did not have the float adjusted correctly. He kept telling me the issue was water in the carb, blah, blah, blah. The float was touching the top of the carb before the valve could shut off. I read somewhere that there should be about 6.5mm between the top of the float and the top of the carb. It definitely has solved that issue. I also replaced the fuel filter which was very clogged. Now I have a new issue. I tried setting the carb back to factory settings, however, the engine won't start on its own or run on its own. I can use just a spray of starter fluid and it will start right up, but it won't stay running without messing with the throttle. I noticed that if I use the starter fluid and pulse the spray over the carb, it smooths out and idles very good. As soon as I stop doingthat it sputters and then dies. I have noticed that the gas does not seem to go down the venturi very consistently. Seems like it comes out in spurts. It appears to be a fuel delivery issue. I was planning on taking it apart and looking around to see if something else is wrong. Any other advice? Rebuild kit?

[majicwrench]

The idle/low speed jets plug constantly on those carbs. You can see them in any manual, the are behind a brass screw in the upper part of carb. Pull em, clean em good.
Keith

[seabeelt]

idle solenoid?

[124JOE]

double check your nuts and bolts for tightness
pull your cap and rotor and clean

[Rupesy]

Pulled the carb again and found water in the float bowl. Also gave the float bowl and jets a good cleaning. Put it back on and started OK however I had to keep the throttle going until it warmed up. Once warmed up, it idled fine. Took it for a spin and ran OK. Came back and it idled OK for a while and then stalled. Got kind of tired by this point, but I bet I got more water in there. I think I am going to pick up some dry gas and dump it in the tank. The car has sat for a while. I am going to fill the tank to the top as well.

Also, it didn't seem like the idle mixture screw did anything when I turned it back and forth several turns. Is it possible that the passage is clogged as well?

[Rupesy]

Thought I would add an update. I have now traced the issue back to the gas tank. It has a lot of sediment inside. We pumped a lot of gas a found it to be red so figured it was rust in the tank. So now I am looking for recommendations. Is it something I can clean myself, should I send it somewhere or get a new/refurbished one??

[dmwhiteoak]

If it were me I would drop the tank and clean it myself. At least I would try. I think whatever trash is in there was put there.I don't believe those tanks will rust , I may be wrong , someone correct me if I am. Dennis

[124JOE]

theres a tank cleaner conditioner sealer kit you can do it your self.joe