OK , I tried it again...this time, the rps dropped if when partially blocked the choke,
with ATP bottomed rpm dropped,
with ATP 7 turns out rpm dropped
I unplugged the vacuum hose to the EGR valve rps dropped too. (ATP bottomed out and 7 turns out)
In all cases rpm drops about 250
So I installed larger primary rods, same result.
Cars still drives great, but it looks like I have no contole over ATP
Anyone a hint what could be wrong ?
Carburetor 17059253, 74 Jets and 0.44 Rods
On a stock olds 403 engine