Stalling while decelerating to a stop

Throw some fuel injector cleaner in a very low fuel tank and go for a quick drive, i used to come up to the halt sign with a dead engine and no brakes. Doing this once a year is enough

 

That typically happens when your injection is set up too rich, or has degraded, and is running too rich. Having the a/c on, accentuates the engine load at very low speed causing a stalling condition. When this doesn't happen in colder months, the air density is all different, not causing this condition ( and your a/c is also probably turned off)
Gary Bobileff

 

Is it a US version 1987 Mondial 3.2? (Although regardless of version, it shouldn't undershoot on free engine deceleration.)

 

As noted, that means the fuel mixture is too rich. Take out a spark plug and you will see it is likely black from over fueling. The cause could simply be the mixture adjustment needs refining, but it could also be a sign of leaks within the fuel distributor. Might be time for a fuel distributor rebuild if it is original, the rubber items in there degrade with time and modern fuels. My car presented similar symptoms initially, and eventually got worse to the point where the car would barely start, and the fuel distributor was the cause.

You might turn the mixture screw one sixteenth of a turn counter clockwise, that will lean things out and might solve for things. Do not play around with this, as small adjustments have big outcomes. But these cars are not so easy to set up with the mixture correctly in the first instance, as ideally you need the gas analyzers that many garages no longer have for emmissions testing.

 

Here is my version with solution.

https://www.ferrarichat.com/forum/threads/euro-car-dying-at-deceleration-why.624958/page-1

 

Dont adjust anything......Have the fuel distributor serviced.

 

You have a few good options to look at but try the injector cleaner in a low fuel tk first before you rip things apart.