What happens when you reach 2800rpm? Do you floor it and it just bogs down? The only time I had that problem, my MAF sensor was dirty. I gave it a few taps and it went away. I was probably lucky. No codes? I'd check the MAF first.
Maybe when you swapped pumps, you got some dirt in the fuel line which got sent into the injectors? Run a bottle of Techron thru it.
I hope there wasn't protective plastic covering the pickup that you forgot to remove..
Also, remember that fresh gaskets need to be retorqured after heat cycles.
Last edited by capt. killingfield; 05-16-2019 at 03:40 PM.