I've had a Holley Blue electric fuel pump (in line) installed in my 1990 305 TBI for about 5 months now. Up until about 2 or 3 weeks ago, all was well. I live in NC, so the temperature here is starting to drop pretty drastically.
Recently, my engine has been wanting to cut out on me.. I want to say it's bogging. I'll hit the throttle to the floor and it'll sputter and I'll get up to about 30 mph, then it'll choke out. So I'll let off the pedal and baby it up until about 45 mph, and then it gets worse. Sometimes I'll even slowly start decelerating, hitting the throttle, throw it in neutral trying to get it back, but nothing works; nothing happens when I hit the throttle it'll just choke. By this point I'll be going about 20 mph and I'll have to pull over and give it a rest.
The problem started about 3 weeks ago when I tried to hop on the interstate. I was fine until about 45 mph, then the rpms stayed the same and I was no longer accelerating, only getting progressively slower which is scary as crap on the highway. So I pulled over, restarted her and she was fine for the next 15 miles, going 80 mph, and then the whole way back too.
Now it's anywhere I go. For no matter how long I drive it.
I was told that the cold weather could be a factor. Something about the temp sens telling the ecm to push too much fuel. And oh yeah, it smells extremely rich when it cuts out on me.
Any ideas?
Since the problem, I've put on MSD coil, cap, rotor and wires, cleaned out my intake and valve covers. Obviously nothing affected the problem, I just did it 'cause it was that time again.

 

Did you remove the in-tank pump?
What prompted you to add the inline pump?

 

I've always found mine to run better (more power, better throttle response) in the colder weather.