idle problems
 

Well here I am again. Thanks for all the help guys. One day I hope to be able to quit bugging you. Here in Arkansas there isn't any one who knows boo about this car. Hell most people don't even know what it is. Is that a fiat??

Anyhow I can't seem to keep the idle. It idled fine once I rebuilt both carbs. Drove it all day no problems. The second day idle is around 100 to 200 rpm? It does not seem to idle on all four cylinders. I pull the plug wires off the distributor one at a time and well sometimes #3 is not firing or then #2 is not firing? Once up to speed runs fine? I still suspect the distributer or maybe time to do valves again? Help I am driving this car to work everyday and it just keeps getting better. SmileWavy

Fiat, huh.....
 

Hello,
Idle problems could be a bunch of things, are the carbs webers or solex, what general shape is the engine in. Is the elect. stock, or 009 or 050 dist. and I'm sure there are a whole lot more things, but generally, I think its in the carbs if it comes and goes.
My idle problem was do to the old solex carbs sucking a ton of air around the shafts. I could put my fingers around them and change the way the engine ran. On warm days it ran ok, but get below 60 and it was crap.
My weber 40's did the trick, idles good around 1000 rpm.
I'm sure you'll get a bunch of commentary on this one.
Good luck and Happy motoring in Arkansas,
Chas.

Carb clarification
 

My carbs are solex and I just put new gaskets on the carbs when I rebuilt them. How tight can you tighten the carbs down on the spacers. I suspect this could be the problem. I was quite leary about overtightening them? :)

carbs
 

I would certainly tighten them enough to insure no leaks, sucking air could cause the problem you discribed, Interesting, it ran good for a day them didn't, perhaps they loosened up... I'm sure someone on this Board knows the torque for the nuts, but I did mine snug to tight, it's a feel thing.
Good luck and Happy motoring,
Chas.

Distributor comments
 

My distributor is a 031 I am not sure how to tell if it is ok I have checked the dwell at various rpms and seems to be fine. Thanks for your help. There seems to be sparks at the distributor so it still seems to point to carbs or maybe spark plugs. They are new but I had a bugger of a time getting them in maybe thay are not tight enough?

Is there any play in the throttle shafts? Can you wiggle them from side to side? Solexes are famous for shaft wear that can cause air to leak into the carbs and make it hard to set and maintain the idle mix. A little play will cause a lot of trouble at idle. The play can also make the butterfly move slightly and sometimes seat differently when they close at idle.

You don’t need to crank down on the carb mounting nuts. A thin film on RTV blue on the thick gaskets and then snug the nuts with a small amount of locktight blue to hold them. It is hard to get a torque wrench on the nuts so it is best to say snug rather than XX ft/lbs

What do the plugs look like? Are the carbs syncronised?

Carbs
 

I have not syncronized my carbs since rebuild. I t is difficult when it does not idle? Can I still do it at a higher rpm? Should the blue sealant be placed between each gasket and spacer as well as between the carb and gasket? The spark plugs are new but I have not pulled them recently. I will check the play though.

I would not worry about the RTV sealant at this point but yes, you can put a THIN film on each gasket. It really helps with seating the gaskets and it cleans up easily the next time you rebuild.

Can you get the car to idle at all? Even a high (1500) or so can be used to rough things in. Can you tell if one side of the motor is pulling better than the other? How well does it run when off idle? Is this the same problem that caused the carb rebuild to start with? Some times something that is stuck in a carb passage or orifice will be dislodged but not ejected during a rebuild. The carb will work until the debris moves and clogs something again. What is the idle timing on the 031? If you have a timing light with an adjustable advance or an indexed pulley you can easily check the advance curve as well as the initial and final timing.

I set a high idle on each carb and then disconnect the linkage at one of the ball cups. Then I sync the carbs and drop the idle as I do. After getting things working well on the idle stops I reconnect the linkage after adjusting them to be even. While running the motor at about 2500 RPM by blocking the motor bell crank (on the back of the dog house) I recheck the sync. Try and not push on the cross bar assembly as this will cause the sync to be different than when the cross bar is pulled by the motor bell crank. You can check the linkage from idle to WOT with the motor off as well just to see that the carbs are both being pulled open in cadence with each other. I measure the butterfly gap with drill bits. Just use different sizes to check that both butterfly sets have the same gap at various throttle positions. Just because they might be sync at 1000 RPM doesn’t always mean that they will be lockstep at 4000

Check the spark plugs. May be fouling if carbs aren't dialed in.

Make sure the idle jets are clear. As noted by Green 912 the rebuild may have dislodged but not ejected something.

Idle saga
 

Well she is idling at 2000 rpm today. I checked the shaft in the carbs, seems quite good. Should I try to synchronize carbs at 2000 rpm or turn idle down. Not to say it will be there tomorrow. The car seems to run ok when up to speed. I tdoes not cut out or seem to smoke. I does however look like the spacers are a little wet in spots. Does this mean gas leakage from gaskets? I guess I should use the site tubes for carb synchronization. The linkage seems synchronized. I do beleive that it is firing on all four cylinders at idle today. The only up to speed irregularity if is if you give it a sudden shot of the accelerator it falls on its face and then picks up?