IIA Dies When Hot

t77911s

Well-known member
Sep 16, 2004
398
0
After driving the IIA for approx 15-20min, car just feels like it run's out of gas, and it dies. Once it cools down it fires right back up and runs for another 10min or so and does it again. I am still gathering the facts on this, but the first thing I want to rule out is vapor lock, as to get it started this last time I poured some fuel into the carb and I could hear it bubbling, I guess from the heat of the exhaust manifold which is right under the intake. I am new the Series IIA's but not new to Carb's, as I used to work in old carburated 911's, so I am learning the idiosyncrasies of the IIA...

So when it died I did the following:
1) Disconnected fuel line at carb and manually pumped fuel to rule out blockage.
2) Cranked car and directed fuel into plastic container to verify FP working.
3) Checked for spark at each plug.
4) Unscrewed plug on bottom of carb fuel inlet and watch fuel come out while starting.
5) Pulled carb top off to validate fuel in the carb bowl.

Bottom line, I am getting spark and fuel (to a degree)...

Any thoughts on going to an elect pump like a facet and bypassing the mech pump, as I am really not sure that the mech pump is pumping the correct amount of volume of fuel as well.... Thoughts? tim
 

awarner

Member
Dec 20, 2004
8
0
Houston
I had a similar issue that plaqued me for months.. I was using a cheap inline fuel filter in between the pump and carb. It rested on top of the valve cover.. As the engine temp increased, the dirty filter and heat, would cause a "vapour lock" and would not allow fuel to continue to the carb. My father inlaw diagnosed almost immediately when we were stranded in a retention pond, miles from home. Once I changed the filter on a regular basis, I never had the problem again. Hopefully it's that simple of a fix for you..
Andy
 
Jan 3, 2005
11,738
67
On Kennith's private island
Probably dying after the choke opens. Most likely the fuel filter, but could be a gummed up carb.

Spray some quality carb cleaner in the carb and allow it to soak. In the mean time change the filter.
 

cdansan

Well-known member
Sep 15, 2008
537
0
Northwestern, Vermont
Old school trick is to make a sheet metal heat shield to go under the carb to reduce heat from the exhaust in the float bowl.
Also route fuel lines away from heat sources and insulate them if possible.
I am not sure if/how it would be done on a IIA, but it worked on my Sunbeam.
 

My6speedz

Well-known member
Feb 15, 2015
134
1
NC
I had an old 240sx that would do this and it was a cracked block. Engine would heat up and expand causing it to loose compression. Pull over go get a bite to eat and it would crank right up. Took me quite a while to figure that one out and I sold it as a roller rather than fixing it. Just a thought.