Stall at curb idle at intersections

[agentfluffy]

My 1978 Fiat 124 Spider has a tendency to stall when coming to a stop at intersections. It is somewhat random and doesn't happen all of the time. The Rev's drop and it stalls almost like it isn't getting gas. It always starts right away after stalling. Just put it back on the road after winter a few weeks ago and the first day it didn't happen, the second day it happened once and since then it is all over the place. Any thoughts would be appreciated. thanks

[RRoller123]

I am following this because my bike does the same thing. I am thinking float bowl level problem.

[aj81spider]

I had a similar problem on my 1974. I cranked the idle speed for a while to compensate. It turns out one of the small caps that was covering an unused vacuum port had fallen off and I was getting extra air sucked into the engine. You might give things a once over to make sure you have no air leaks.

[SteinOnkel]

Vacuum leak.

[courtenay]

Sounds like vacuum leak to me too. In my case it was a pooched brake booster.

[18Fiatsandcounting]

I agree that it's likely either a float level issue or a vacuum leak, and my guess would be vacuum leak. If these aren't the issue, another possibility is that your idle mixture is not quite right, so you could try adjusting that. It's the screw at the very base of the carb.

-Bryan

[agentfluffy]

Thanks to everyone who posted. There is a vacuum hose that goes from the air filter pan to no where. I found it when I was painting the air filter pan but haven't been able to figure out where it attaches to. Any help with that might solve the problem. The guy I bought it from told us about the stall problem, but if you didn't take the air filter pan off you would no the hose wasn't attached. Thanks so much.

[18Fiatsandcounting]

From what I can recall from a '78 spider that I had many moons ago, there were two hoses from the air filter housing: One was a 1" or so diameter hose that went to the oil separator unit under the intake manifold, and its purpose was to feed engine blow-by back into the carb, and 2) a 1/4" or so hose that went to the base of the carb near the primary throttle plate. Both are essentially emission control items.

But, neither of these hoses has vacuum at idle, so you might have another hose that has a vacuum leak.

-Bryan

[agentfluffy]

Thanks Bryan, that will at least help me sort out the one hose not connected to anything! Much appreciated.