I believe it is an efi , the engine is 5.7 gsi PLKD Part #3868624
We have called it a throttle body
I have been adjusting the float in the fuel reservoir and that has helped. I have adjusted it to hold less gas??
We thought possible a sensor was telling the fuel pumps that the engine was cold and sending to much fuel to the injectors.
Thanks for answering.
Either way it is considered fuel injected. It very well could be your theory of a bad coolant sensor, bad MAT/MAP sensor that is located on the intake manifold. It could also be to much or little fuel pressure. You would have to test the fuel pressures to be sure.