IDFs in wintertime

[grrrdot]

Hi,
I drive my Fiat the most in winter. In 17ish years only once have I had trouble with the carb icing up and it sucked.
Since then I’ve had FI or made sure to have an air filter that drew air from over the exhaust manifold.
I’ve found a good deal on a set of IDFs with a turtle back air cleaner but I’m concerned about cold weather driving.
Anyone have any experience with IDFs icing up?
-G

[sptcoupe]

Its been many years since we lived in northern Wisconsin and Ohio, but I never had any issues with IDFs during those extremely cold winters. The carbs available then had manual enrichment circuits on them that were cable actuated from the cabin. All I had to do on those bitter cold days was pump the accelerator pedal just a bit, start to crank her over and then pull the cable out about hallway, and she would fire up just fine. After about 30 seconds, you could push the cable back in and drive off normally.

I spent one winter in Wisconsin with newer carbs with no enrichment circuit. With this set up, I recall I just pumped the accelerator as I cranked her over, and she started fine.

The IDFs don't have the choke butterfly sitting on top of the carb like the standard 2-barrel carbs the cars came with in the US. I had a good bit of trouble with those carbs icing in the winter while starting. You would set the choke, and the instant you cranked her, the moisture vapor in the carb would freeze the butterfly closed, so you were stuck with the choke full on. It was so bad I devised a "quick release" for the air filter box top so I could easily open it and pop and open the choke butterfly manually.

Here in Houston we get the rare morning with temps in the upper 30's, and I've never had any issue with start up with IDFs.

[grrrdot]

Great news!
These have the enrichment circuits, I'll have to track down a cable to actuate them.

When I had icing it was caking up over the auxiliary venturi and disrupting the airflow.
I had to pull over a few times before I figured it out because at idle the ice would melt.
It was equally cool and annoying.

-G

[seabeelt]

We drive ours until the snow flies ( and we have had some bitter cold days (heated seats ) and never had a problem with carb ice up