I've been noticing a new problem recently on my bronco. I believe it started last summer. But I've really only put on 200 miles since then. Anyway, as the engine warms, the issue seems more noticeable.

As I accelerate moderately in the longer gears, the engine picks up rpms slowly, but if I press the pedal a little harder, it doesn't seem to pickup rpm's any faster for a second, and then something changes and it will begin to accelerate harder. Like the air supply is closed off for that second and then the butterfly opens and she charges with full power. You will really notice this on the highway as you modulate the pedal to maintain speeds up slight hills etc. It feels like it doesn't want to accelerate and then it'll charge ahead like it should.

My memory is fuzzy, but I believe I've had this issue in the past, prior to the recent rebuild and engine harness. I could be wrong.

I wish I could blame it on turbo lag, but no forced induction here, but a similar feel.

Where should I start looking?

You might check for fuel line restrictions. Clog filter, pinched line.

Probably worth checking the regulator (via pressure gauge). Maybe its slugish. Quick tip-in's require lots more fuel cruising or slow tip-in's

I'll check the fuel system, but I believe it to be ok, only because last year I had lots of fuel issues and I replaced the filter, moved pumps around, replaced the fuel reg etc.
Thanks for the tip!

I had the same issue though not fuel injected, cleaned out lines and new filter which was needed anyway but in my case it was a heat issue so I insulated my fuel lines and that fixed it. Doubt that’s your issue but just tossing it out in case

Vapor lock is always something to watch out for but I don't think my temps are warm enough for that to be a concern. I appreciate the brainstorming in any case.