Rebuilt 78 Fiat Spider Carb issues

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RedSpider78
Posts: 2
Joined: Thu Mar 23, 2023 2:20 am
Your car is a: 78 Spider

Rebuilt 78 Fiat Spider Carb issues

Post by RedSpider78 »

I rebuilt the engine and have been working on it for several years (due to lack of time) and after putting it together, it wouldn't start, so I finally took it to a local FIAT specialist, AllisonsAutomotive in Upland, CA. they fixed the electrical and fuel pump issues, got it running, but cost me more than I expected!$$$$ but, He said the carburetor base was warped and I needed a new one $$$!? :o Then I remembered that I had an old/ spare carburetor at home, which was good so I got the rebuild kit and rebuilt it and I installed it. But when I tried to start it up, and adding starter fluid spray to help start it, but it would not stay on!? I'm not an expert mechanic, thus I figured it's either the fuel pump isn't getting fuel to the carb. or the Carb isn't working, although I did everything by the instructions in the Kit and my Haynes manual (plus some online research). It's been over 6months sitting in my garage, and don't think Allisons will work on a carberator that I did not buy from them, without charging me $$!? (and I WOULD HAVE TO TOW it there from over 50 miles away)
So I am ordering a replacement 32/36 DEFV from autoricambi.com However, they told me "If the 34ADF (or 32ADFA) has an idle solenoid, make sure it's working. The engine will not idle if the idle solenoid is not working, as it shuts off the idle passage"
Any ideas or help would be appreciated... :D
18Fiatsandcounting
Posts: 3799
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Rebuilt 78 Fiat Spider Carb issues

Post by 18Fiatsandcounting »

There are a lot of different aspects to this, so I'll start at the top:

1. What is the carburetor model that Allison's was able to get running? If stock for a 1978, it would be an ADFA. Was your spare carb the same?

2. If the carburetor base is warped, it can be sanded flat if not too bad, or use 2 gaskets. If it's more serious warping, then yes, you would need a new carb base.

3. Simple test to see if there is fuel in the carburetor (in the float bowl): With the engine off, hold the choke plate open with your finger as you peer down in the barrel with a flashlight. As you work the throttle, you should see a stream of fuel squirting into the barrel an inch or two down inside, and only from one side (the side towards the left front fender).

4. Yes, If you have a specific model of the ADFA, it has what is called an idle stop solenoid. If not connected to power when the ignition is on, then the car won't idle. But, the car should still start and rev OK. But just not idle. This kinda sounds like what is happening with your spare carb, although there could be other issues like it simply isn't adjusted right. Do you know if the automatic choke works?

-Bryan
calvinconrad
Posts: 104
Joined: Sat Mar 19, 2011 10:22 pm
Your car is a: 1976 spider
Location: Cape Coral FL

Re: Rebuilt 78 Fiat Spider Carb issues

Post by calvinconrad »

make sure the new carb is a weber not the empi copy. had empi for a few years and had to replace it. Empi had quality issues.
1976 124
RedSpider78
Posts: 2
Joined: Thu Mar 23, 2023 2:20 am
Your car is a: 78 Spider

Re: Rebuilt 78 Fiat Spider Carb issues

Post by RedSpider78 »

Thanks for your info... A. I did check the solenoid test and I heard a click when I checked it, with the ignition on, I heard it click when disconnect or connect the wire! and I when I rebuilt the carburetor I replaced the base (throttle body assy.) with a good flat & clean base spacer and new gaskets that came with the kit.
B. So I charged it up and before starting the engine I put a little gas in the carb intake and it cranked and started, but no acceleration when I tried to pump the gas, it just died and when I tried to start it over NADA!? it just the starter cranking the engine!?
c. finally, when I manually opened the intake barrel and pump the throttle, I don't see any gas coming out of the jets!? (an I do see 1/4 of gas in the clear glass fuel filter)
18Fiatsandcounting
Posts: 3799
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Rebuilt 78 Fiat Spider Carb issues

Post by 18Fiatsandcounting »

A couple possibilities:

1) Your fuel pump is really weak (slow). It might be getting fuel to the clear filter (slowly), but it's not pumping strongly enough to fill the carb's float bowl.

2) Your needle valve on the carb float bowl is stuck closed (or the float level setting is way off).

I'm guessing that you could keep the engine running by squirting starting fluid into the carb once it's started, but this is both unsafe and not a good way to drive around town. If this is the case, it does tell you that the carb isn't getting fuel and you just need to figure out why.

-Bryan
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