Idle surge- 1995 4.0

[toddztoys]

Just got this truck, Ext cab 4x4 4.0. Once it warms up, the Idle will surge up then down every 5-10 seconds. Doesn't matter what gear, it will even do it at speed. Any ideas?

 

[mentalbreakdown00]

Well , pull codes if any, but most of the time surging is an air fuel ratio problem like a big vacuum leak or the sorts.

 

[Destroyer000]

sounds like a vacuum leak spray some carb cleaner around the intake an check out the egr tube for holes.

 

[dogboy]

My thoughts would be EGR system, or a vacuum leak somewhere.

Both will cause problems similar to this.