Carb? problem 75 spider

[dirkdantuma]

Sorry in advance for what will probably be a long post and for some of which I have posted before. My 75 with what I assume was the original ADFA 32 carb ran pretty well for the last couple of summers but usually did not idle without either pulling out the throttle or revving it a bit. At the beginning of this summer (geez it is all ready the end of August), I thought I'd take a look. I found out that the wrong size idle solenoid was put in and the carb was loose on the manifold. After fixing those problems, it did not idle right nor run right. Giving it some gas caused it to sputter and sometimes backfire. So I took apart the carb, cleaned it and adjusted the float. Changed the fuel filter and plugs. After that it idled better but when I gave it some gas it would just sputter and die. Too much fuel right? Has to be the float, right?? Took the carb apart again and the float seemed fine and within the right settings. So today, I loosen up the idle solenoid and the carb from the manifold, gave it some gas and it revved up beautifully. What the #@?#$. What do I do now. It's got to be that it is not getting enough air, right? Anyone got any suggestions or know a mechanic in Saint Paul, Minnesota? The few I've called near me won't touch it. Could the PO have plugged something? All the emission stuff has been taken off.

Thanks folks for listening to one frustrated guy who has already missed half of the season I'm able to drive with the top down.

Dirk

[baltobernie]

We're having our first few days of cool weather here, so I'm feeling your sense of urgency, Dirk.

Sorry I have no specific advice, but since you have no emissions equipment installed, why not bite the bullet and get a new 32/36 or 38mm carb and be done with it?

A mechanic would charge you almost as much to troubleshoot and probably rebuild what you have.

[So Cal Mark]

have you tried blowing through the various carb circuits with compressed air? It's very common for the idle circuit to get plugged up. Loosening the solenoid allows lots more fuel to pass the idle jet

[mbouse]

Sorry in advance for what will probably be a long post and for some of which I have posted before.

(geez it is all ready the end of August)

Anyone got any suggestions or know a mechanic in Saint Paul, Minnesota? The few I've called near me won't touch it. Could the PO have plugged something? All the emission stuff has been taken off.

Thanks folks for listening to one frustrated guy who has already missed half of the season I'm able to drive with the top down.

Dirk

1. don't apologize for requesting help. this forum is full of good advice just waiting to be asked for.
2. no one will touch it, because they don't teach carburetors in fixit schools anymore. everything these kids see is FI
3. gotta agree that seeing a mechanic will be as expensive as buying a new carb and installing that yourself. i think you can still getta electric choke 32/36 with zero emission ports for right around $300 delivered.
4. you should easily be able to see a plug left by the PO. is the fuel return port plugged? sounds like it might be..
5. right! i see only about 8-9 weeks of driving left, if we are lucky.

[Danno]

i dunno, just throwing out another idea. Check your ignition timing, and more importantly your condensors.

[dirkdantuma]

Thanks folks for all the replies. I looked at a DFAV 32/36 carb but the mounting plate was much thinner, throttle cable hook-up was different, no fuel return and a different mount for the air cleaner so I went back to try to fix up the old one. I did spray all the little holes with carb cleaner but I did not blow them out with compressed air. I guess I'll try that this weekend. Is there a carb that is easiest to switch out or should I just replace it with another ADFA. I'll shop around but the ADFA seems to be quite a bit more expensive. Thanks again for your help. Here's hoping I can get it running for a fall color drive!

Dirk

[MinnBri]

hi I had the same problem....auto value has a carb kit for @ $22...... there is "crap" in the accelerator pump and booster nozzle... AKA when you push the throttle down the accelerator pump pusher fuel through the booster nozzle and you should see a good amount of fuel squirt in the carb... I would guess that the fuel is just dribbling into the carb... There are pieces of fuel line that deteriorate and plug that up.....

[dirkdantuma]

I've been out of the loop for awhile so a belated thanks to Minnbri for the reply. It sure is a pretty drive in and around New Ulm. I sure wish my Fiat was running so I could drive down there and have a nice Schell Octoberfest before the snow flys.

Anyways, I bought a new carb, a 34 ADF, which bolted right on after a bit of monkeying around with the throttle linkage. But it still doesn't run right. It will idle roughly and a soon as you give it gas it sputters, coughs and backfires. AND then for no apparent reason, all of a sudden after idling for several minutes, it smooths out and idles high (3000-4000 rpm) and when you give it gas it revs up nicely. AND then again for no apparent reason, it goes back to idling roughly and sputtering when you give it gas.

So now what. Is it vacuum? What is the cylinder thing that has a tube off of the tee from the manifold and then a tube going into the carb? It is bolted on the driver side fender well and it does say Weber on it. Is there something inside that is serviceable?

Thanks folks for any and all help.

Dirk
Hoping I still have maybe a month to go for a ride

[bradartigue]

The cylinder thing on the fenderwall is a high idle solenoid. It connects to the carburetor and holds the idle high when you are decelerating in 3rd or 4th gear. It sounds like yours is not working correctly; you don't need it, so remove it and plug both the port on the manifold and on the carburetor. This should correct your erratic high idle problem.

Fix that first then report back.

[majicwrench]

Just my opinion, but disconnecting and plugging various things that youu "don't need" is not a good idea. All that stuff is there for a reason, it worked like a champ when new, it will work well again when properly repaired.
Good luck,
Keith

[So Cal Mark]

"it worked like a champ when new", well not always. Driveability in the 70s and 80s was really bad on some cars due to emission related issues; either tuning or extra equipment that affected fuel mixture and ignition timing.

[majicwrench]

I worked in a bunch of different car dealerships in the 70's and 80's ( even a Fiat dealership!) and all the new cars I ever saw ran pretty dang good. Probably the WORSE running new cars I ever saw were the early 80's GM products, cruising at 35mph, lock-up converter locked up, chugging along, EGR pulsing, jeesh it was terrible. But they started well, idled well, got reasonable mileage, and kept me employed.
Keith

[dirkdantuma]

I don't mind fixing rather than disconnecting but what I am frustrated with is fixing something that was obvious broken and then having it run worse. As I posted originally, the car ran fine (but didn't idle right) with the carb loose on the manifold and the wrong size idle solenoid. Now I can't even back it out of the driveway.

I did disconnect the high idle solenoid (thanks Brad for the tip and identification) and it now idles at the proper rpm BUT all of a sudden something happens and it starts to idle roughly and when I give it gas it sputters and backfires. After idling roughly for several minutes, something clicks (not audibly) and it then runs properly. And then just a quickly it goes back to choking and sputtering. I've changed the fuel filter, twice, plugs, points, condensers, air filter, and checked the timing. The fuel pump is working. I would think it is getting too much fuel by the way it sputters when I give it gas so it shouldn't be the fuel lines, right? It's a new carb. Anyone want a haunted fiat? My season is running out.

[racydave]

Maybee its the fuel, Id take a sample in a glass jar and give it a good look. Also another problem as the GM cars used to do (back in my 30+ dealership years) The wires to the pick-up in the distributor may be about to break and can give an intermittant problem. I never knew of an Idle solenoid( plunger ) being good for anything but boosting the idle when the A/C was on, lose it!

[majicwrench]

Dirkdan,
I feel your pain.
SOund like first you need to decide just where the problem lies...
If it is running too rich it should be blowing black smoke, and will usually clear up if reved and held up . ALso, if running rich, would clear up if you pinched off the fuel line. Bear in mind, if you keepthe line pinched,. obviously it will run out of gas.
If it is running too lean it can certainly pop and backfire. You can try pushing the choke valve shut while it is doing this and see if it improved. Shutting the choke valve will make it suck more gas, and if too lean it should smooth out. you're wearing saftey glasses right?
If neither of the above makes any diff, it may be something other than a fuel issue. Pull the coil wire from dist, hook a spark plug too it and lay it on something metal, now crank engine. Should see nice blue spark capable of jumping a .050 gap. spark should be consistent..zap.zap.zap.zap. ALso, engine should crank with a consistant sound with dist unplugged, RRRRRRRRRRRRRRR, not RRRuhRRRuhRRRruhRRRuh. If it is doing the RRRuh thing that indicated a cylinder low on compression.
Good luck,
Keith