Hello, looking for advise. I am having a issue with my 1963 MKX with the 3.8 and triple HD8s. I am getting a surge at part throttle and full throttle. I have verified it is a fuel issue because I can engage the starting carb solenoid and the car positively responds and runs great.
The engine has good compression, timing has been checked, floats adjusted to just below jets. I can get the the engine to idle good.
I have raised the jets needles above the grooves in the pistons and the problem is resolved but the idle is too rich and wont run good. I have looked for vacuum leaks with starting fluid around gaskets and seal and have found none.
The needles are UM.
This is the first time I have ran this car so I do not have a baseline.
My question is: All this time I have run the car without the air filter plenum. Would this cause the engine to run lean at highway speeds under load? Should I try some UO needles?
Thank you in advance.