carb removal on 71

[Budduncan]

I local "established" carb shop is willing to rebuild my carb on my 71. I can bring the car in and leave it or bring in the carb. What are the pitfalls of pulling an old carb? While I am pretty mechanical, I do not routinely do this and other than dropping things into the intake manifold, there are probably some other "bewares" to watch. Thanks for your comments.
Bud in Seattle.

[narfire]

Seattle? have you considered Apex performance? They seem to be the go-to people in the Seattle area for the older Italian cars, especially the Alfa's mechanical Spica FI.
I suppose there might be two schools of thought.. drop the car off and they remove, rebuild, and re-install and then hopefully have the where-with-all to get the car running and adjust for best performance. Drop the carb off and the labour rate will be less but you have to re-install and do the set up....

[Budduncan]

Yes..Apex is the shop I talked to. They can probably tell me the pitfalls, but there is so much info on this forum I thought I would toss my pitfall question out there. The easiest thing would be to just take the car to them as it is running, but I know the carb could use a rebuild. Thanks for weighing in.
Bud

[dmwhiteoak]

There is not much to pulling the carb.A couple of nuts may be a little tricky but not too bad. If you don't have a photographic memory or close to it, take some pics of it before removal. It's really not hard. When you install it back on the car and ready for tuning there is alot of info on here to help with that. If not just ask. And by the way, don't drop nothing down the intake and stuff a rag in it until your ready to place the carb back on. Just my 2 cents.

[majicwrench]

LIke was said, nice thing about taking whole car is shop will adjust carb after it is back on. If you are not comfortable removing carb you are likely not comfortable adjusting carb.
Carb is SUPER SIMPLE to repair, if you take it off yourself you are likely capable of rebuilding it too.
What makes you think carb needs rebuilt?? Very common for people to bring in car saying "carb needs rebuilt" when something else is the issue. Take em the whole car. Tell em your concerns, what doesn't run/work right.
Keith

[Budduncan]

Thanks guys for your comments. Everyone is making sense. While I agree that pulling the carb would not be a daunting task, there is always a learning curve with these things, and I doubt I will ever need to do it again, so I think the advice about taking the entire car in makes the most sense. FYI..when the car sits for more than 48 hours, it takes a lot of throttle pumping, choke and quite a while to start. Once started, it will start virtually instantly, hot or cold. But after sitting it is like the carb loses all fuel. In addition, when driving, there is kind of a flat spot on acceleration. I have rebuilt the electrical system and the car is running fine except for the above. Apex thought the carb attention would probably solve the slow start after sitting. I have owned the car since 1972, and the carb has not been touched in 25 years that I can recall anyway. It has a mechanical fuel pump and original ignition, not electronic. This is a great site for information. Thanks to all of you who contribute your guidance. I always get lots of comments when driving around Seattle on a top down day (mine is virtually always down because I do not drive it in the rain).

[majicwrench]

The long crank/pump/chole issue will not be resolved by carb repair. Flat spot may be.
Keith

[Budduncan]

Keith, you have me me curious. You seem to know a lot about Fiat and carbs. You are probably correct about the cranking after sitting issue. What are your thoughts about what would cause that? My logic wants to say fuel related, but not necessarily carb. Assume fuel pump is also OK, and I believe the fuel filter is also not an issue. Fuel supply hoses seem OK, but granted are old. I am still going to take the whole car in, and it has had this cold start problem as long as I can recall, but as long as I light it off every day or two it is not much of an issue. Why would fuel drain out of the carb and where is it going? Thanks for your thoughts.
Bud

[hamlet]

Looks like you won't have to take off the carb, but for posterity's sake, I believe the carb removal on these cars is very easy, but one thing that might be helpful is to have those rachet wrenches. I think the bolts on my adfa are 13 mm? I couldn't get to them with a socket. You'll also want to disconnect the solenoid, the choke (probably a water choke) -- this has a little thing that has to be placed in the middle of the lip off the coil, though I could be wrong about that -- and plug the gas lines and make sure you have which one is fuel line to the intake and the return hose -- on the carburetor and the hoses -- and of course, the air filter. Good luck!

[So Cal Mark]

the long crank time could certainly be a carb issue. When the pump diaphram leaks, the float bowl is emptied causing a long crank time until the carb is filled again.

[azruss]

If its a stock 71 it should have a manual choke, so no water hose issues. Also the 4 13mm nuts that hold the carb on are too close to the body for a ratcheting box end. you'll have to do it the hard way. Still its less than a 15 min job to pull the carb.

[majicwrench]

Mark is right, the long crank can be a leaky accel pump diaphram, it would leak externally and smell, nice thing it is easy to check, just stick your finger under pump cover ( LF side of carb, 4 screws) and see if it is wet.
More likely in my experience is fuel pump check valve letting fuel drain back from line. Also easy to check, get a cheapy round vac/pressure gauge, pull fuel line off carb, securely hook gauge to line. Crank engine, should show some pressure 2-4 psi. Now watch gauge. If drops quickly, you have a problem. All it takes is a tiny bit of debris under flapper valve and fuel drains back.
Keith

[Budduncan]

Well, gents. I have learned a lot already. One of the things I love about this site is the generous assistance. Ask and ye shall receive...or something like that. Yep, choke is manual and is my prime anti theft device. Young thieves wouldn't know a manual choke in Seattle anyway and the would run the battery down trying to start it with out choke. Thanks again, and I will have the check valve in the fuel line investigated. Now, I hope it is not located in the gas tank. I would assume it must reside between the fuel pump and carb. I am in my office and cannot go look until tonight. Again thanks for all the comments and help. I have lots of metric wrenches, as well as sockets and ratchets, so it is not too difficult to grab an appropriate tool.
Bud

[majicwrench]

Check valve is built into the fuel pump, at least on my 72 and most other vehicles with mechanical pumps. Typical fiat pump is easy to take apart and clean valve. You can buy a seperate check valve that goes in line, a seach of site should produce some hits.
Keith

[Budduncan]

Keith; Now I am laughing. When I was about 10 years old, mid 1950's my father dropped a fuel pump on the bench and invited me to take it apart. I was wearing my only white Sunday school shirt and he did not mention "the spring". Well it blew up on me and covered me with fuel and oil residue. He as laughing, but my mother was not at all amused and before she was done with us, Dad was no longer laughing. I have since treated fuel pumps with respect and would not open one wearing my dress white shirts. I thought you might enjoy that thread....thanks again for the help. Does your 72 still have the smooth hood? What year the did hood change? I do not see many of the smoothies around.
Bud