Hello!!!! Having an issue with the idle up on my 99 7.3

[AKTIVE1]

HELLO EVERYONE!!!
has anyone had trouble with there automatic idle up after starting, my truck usually runs for about 4 min before it kicks in, this morning i started it before i left for work and i usually hear it idle up. today it sounded like it was trying to idle up but kept getting knocked down, almost like it was surging above idle up rpm and then below normal idle. it would do that for a few seconds than go back to low idle....any ideas....thanks allan

 

[JLDickmon]

the backpressure valve is tied to a sensor on the top right (left if looking at it from the bumper) side of the water pump.. a lot of times the tube will get all sooted up and clog.. just a simple matter of cleaning it out..