2002 7.3 PSD Excursion start up mystery???

[Justgreasenofries]

Here are the symptoms,, any solutions? After sitting over night when I start the engine it will rev up and down and up and down the tach will match the revs of the engine it does this for about 10-30 seconds then smooths right out, or if I touch the pedal it straightens right out. Any help would be apprecaited. No codes are thrown plugs cycle normally etc.. Thanks. Randall

[SCUFFY828]

possibly cold ipr regulator sticking, if ts runs ok after that ,dont think i would sweat it to bad