Every time i turn my a/c on my truck the rpm goes up and down

Lean fuel condition could be caused by one of the following below:

1.Vacuum leaks
2.EGR and PCV valve.
3.Low fuel pressure.
4.Dirty fuel injectors.
5.Mass Air Flow Sensor.
6.Oxygen Sensor.

Thanks I'll try some of these.

Engine Performance problem
2001 Ford F150 V8 Four Wheel Drive Automatic

first thanks to all the help so far..
after replacing battery fires up great and runs well throughout day. morning idle is low does not want to stay running. takes about 5 minutes to reach proper idle. had weatherized next morning started fine but today same idle problem.

sounds like another tech is helping you? hit reply to question at the bottom of the page of your original topic that way you keep all the information there and the tech that was helping you will be able to continue doing so.

my 2001f150 5.4 idles rough upon startup and the rpms will jump from 1000 to about 1300 to 1500 and crash to 0 causing the truck to go dead it doesnt go dead all the time only in spurts

Hi firelt4, Welcome to 2carpros and TY for the donation

Clean out the idle air control valve and test throttle position and mass airflow sensors

why does my 2000 ford f 150 idle hard up and down in park

could be a number of reasons, Has the truck had a tune up? Is there any error codes? Even some times a small piece of carbon can get into the throttle body and partially clog a air hole. As I say there could be one of a number of things.

At low rpm's idle surges drastically. I replaced intake, IAC, DPFE, TPS, COP, plugs. All of the vacuum lines. The EGR, and MAF. Could the 02 sensors and catalytic converters cause such a surging idle?

Also, I replaced all fuel injectors.

clean throttle plate and IAC hole on both sides with choke cleaner. Then look for an air leak like valve cover grommets, and vacuum lines.

also scan for codes and check fuel pressure with a gauge auto parts rent it. See link.
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator