My ‘72 340 Demon ( stock except ‘ mild’ cam ?? ) just started this problem . It starts fine then after warming up 10-20 minutes it struggles and dies driving or at idle ( ambient temperature was 80’ ) No backfire. Will restart immediately but does the same. Spraying fuel in carb does not help when struggling.
My tests and new and near new parts-
fuel tank ,lines ,filter ( it stays full) , fuel cap vent ok & air filter
Thermoquad rebuilt
Fuel pump- 6 psi, 10 inches vacuum , 7 oz delivery in 10 sec of cranking
Coil and ECU - both tested at parts store recently
Dual ballast , magnetic pickup, spark plugs
Timing (initial) 30’ BTC
I use non alcohol fuel
Coolant temperature normal
I am thinking this has to be simple but I am confused as is a local mechanic . I believe one of you could diagnose this in 15 minutes if you were here. I would appreciate any ideas. Thanks.
Yote