This only sounds like a silly thing to mention.
The EFI water pumps spin the opposite direction of the Carbed due to the EFI having the Serpentine belt setup.
If you put on an EFI pump, if you have a late model serpentine belt, any sort of combination of that, you need to set it up similar to whatever year you got it out of or replace the pump with what your setup needs.
I only mention this because without a thermostat in the system, a water pump impeller that is spinning backwards will move a bit of coolant through the engine. I don't know if a serpentine pump will swap in place of a V belt pump, but I've seen enough parts counter screw-ups, miss-boxed parts, and badly built (impeller on backward or wrong impeller) parts that I thought it deserved mentioning. After all, if it was an easy fix, he probably wouldn't have posted to the forum.
Sometimes it pays to think 'outside of the box'.
1994 F150, 4.9L/ZF 5 speed, C-Vic police driveshaft
EFI head w/mild port work, 3 angle valve job
1996 long block with stock hyper pistons, ARP rod bolts
Stock speed density PCM
Stock cam installed straight up (aluminum cam gear)
Hedman header, full mandrel bent duals, crossover, super turbos