1994 f250 5.8L idle surging...

[hellah fresh]

I have a 1994 f250 5.8L and the idle surges up and down randomly. We checked the map sensor it is ok... tried installing another spare IAC sensor and its seems ok i think. Changed out the battery... what can be causing this. It will idle normal for about 5 minutes then idles up and down like crazy. What gives?

[mr tiler]

1992 f250 5.8 efi ex ambulance when idling does same. ive replaced the o2 cencor, idle moter callak converter. when aircon is on idling is fine , when tempreture is over half way three quaters iddle is fine. The auto electrician cant work it out.

[LoseDevil]

Is there a MAF(mass air flow) on this motor? I had a 4.6 with similar issues and all that was needed was to clean the sensor in the MAF.

[jardine]

I just started having this surging issue this weekend. Any ideas on $ estimates to have it fixed? Not something i can do myself unfortunately. Also - what if I don't get it fixed? Looking to get rid of this truck soon so don't want to put $$ into it but don't want to risk a full breakdown either....can I get by with it doing this for awhile?

Forgot to add - I have the 94 f-250 5.8L also......

[danminn]

unplug speed senser on trans on rt side should help idle if does replace

[builtf250tuff]

also make sure ground connections on block are good and test ur powerpack or distributor which ever u have

[mr tiler]

thanks i will give it go see what happens. Ill let you know if it works..Hope it does,thanks.