Idle surge problems

[BichoteAWD]

ok so been fighting with this for a few months now.I start up cold idle is steady 1000-1100 rpms. after a few minutes idleing it warms up and idle creaps up to 1500ish than fuel cut drops to 1000rpms and keeps repeating. Revs and drives fine no cel just bad idle. Heres the crazy thing when idle is surging up and down
i turn on the headlights and bamn! idle is smooth again. will surge after a while of driving. i have no idea what it could be. has anyone ever heard of this before?

 

[turboglenn]

A lot of times the cruise cable will ne too tight and just loosening it up helps a ton. I dealt with that surge for a couple years until reading about the cable on here. Also vacum leaks and especially a bad FIAV will cause it also. But check the simple often overlooked cables of the cruise system first if they're tight with no slackay all loan them ah the cruise box by adjusting those threaded portions at the "in and out" areas

 

[BichoteAWD]

no cruise cable just straight accelerator pedal. no fiav im running jmf intake with a 75mm throttle mustang tps. i was still having same problem with factory setup with all sensors

 

[Bud92gsx]

Mine was doing this intermittently..It used to do it then it stopped then just recently it started doing it again...And turning on the headlights used to work, now it doesn't..So i messed with the idle screw backed it all the way out and back in..That fixed it for about 20 minutes, then it started doing it again..

 

[BichoteAWD]

log on idle

 

[Bud92gsx]

Yo need to put your mods in your profile btw..

 

[BichoteAWD]

mods been added