1988 Chevy 1/2 ton high idle?

[Lumpy]

Hello,

  I have a 1988 Chevy 1/2 ton with a 305 TBI in it. When I first start my truck in the morning it has a high idle then returns to a nice low idle when warm. But after I drive for say at least 10 miles the idle is a bit too high. It isn't terribly high but high enough to jerk you a bit when putting it in gear (700r4). Any ideas what may be the problem? Thanks..............Lumpy

[Shaners]

Lumpy,

 

I'd check the PCV, EGR and since your truck is getting a little older I'd also check or maybe even replace your vaccuum lines.

 

Shane