Help With Final Tuning On 88 Mighty Max 2.0

Hello All
I have a 88 mighty max 2.0 A/T w/overdrive that I have rebuilt the engine and installed a Weber 32/36 DFEV from Redline. I am having hesitation issues when I apply throttle and have to "feather" the throttle so it doesnt die at starts. this issue is only under load. When in park, I can press the gas peddle and it does not cut out or hesitate. I am also experiencing slow accelaration and climbing hills is a chore! I am also only getting 10-12 mpg city. I have a fuel pressure regulator installed and set to 2psi per instructions from weber. I also have the mechanical fuel pump installed.

Do I need to bump up the psi or do I install a electric fuel pump? could my issue be the jets? Do I need to have the ECU reprogrammed?
It was really my hope that this lil truck would purr like a champ and be a great daily runner after the rebuild. Any help or suggestions would be great and helpful.
Thanks
Nick

Almmost sounds like a vacuum leak. Intake manifolds can be tricky to seal at times. You may also check to see if your timing is correct,and if the vacuum advance diaphragm is working.

I was readingother posts,the thought seems to be run fuel preassure at 3-3.5 lbs. Hope this may help.