Intermittent idle issue
 

Hey guys, Ive been having intermittent issues when stopping at red lights. Usual only when the van is at temp.

When it acts up the idle is around 550-600 rpm and in drive, it is rough and feels as though it trys to lurch forward. When this is happening and I put it in neutral the idle improves and all seems normal. Put it back in Drive and she gets rough again. If I accelerate most times it smooths out and is fine but the odd time it will sputter and then go.

Any thoughts? I thought maybe a transmission related thing considering when Its put in neutral it smooths out but who knows.... The computer side of these things is new to me, sensors etc .

Mechanically im good and will tackle anything, built my bronco from the ground up but the dam computers and senors interfering with good ol AFR has got me boggled!

Thanks