1979 308 GTS spits from left bank carbs

[Indy308]

I just purchased a 1979 308 GTS that spits periodically from the left bank of carbs. It does not seem to do this under acceleration. It also idles great when cool but idles between 1K and 2K when driving. I have been told to reset the points on the left bank to cure the spitting problem. Is this correct? Could the idle problem be caused by points?

[Dinosar]

The bad part about Ferrari's facination with redundancy (check out a 512BB for the ultimate) is that there is twice the chance of something going wrong - the good part - along with the flat plane crank, is that you can isolate problems a bit. If the car had the digiplex I would recommend looking at the unit for that bank. However...

Sounds more like an air/fuel issue but I suppose points could do something like that.

High idle when warm is sometimes an indication of an air leak on the intake side. If you suspect this you can squirt a bit of WD40 around the base of the offending carbs while the cold engine is running. If the RPM's go up a bit you probably have an air leak (WD40 acts like a fuel). Its messy but can sometimes isolate air leaks - if thats the problem. Also check your timing advance on that bank. Good luck and let us know when you isloate the gremlin.

[Racer86]

yes! point gap does change the timing. and can retard or advance the timing. My "guess" is retarded timing which will allow a higher idle speed, but it just my "guess"

[Josh@ECS]

I've watched someone chase around the "lean pop" and idle speed issues for literally days before, it seems in my experience a vacuum leak followed by bad mixture settings and bad CFM adjustments work together to cause this quite often. Definately spray to check for vacuum leaks, people tend to over tighten the carb and warp the base causing a leak, depending on the mileage the throttle shaft can allow vacuum leak also. Make sure the idle screws are all turned out at 2 1/2 turns as a base idle mixture. Once you're certain there's no leak check your timing at idle and then at 4k rpm I believe to verify. Then use a synchrometer to measure the vacuum pull from each cylinder and adjust as needed. Updating from points to Pertronix is always a good step as well.