My "97" e150 is iddleling funny
 

when I come to a full stop my van seems to want to take off. The indication is when it rocks from front to back when my foot is on the brake. But when I put it into neutral it stops and as soon as i pop it back into gear (D) it rocks again until I give it gas.
Any ideas anyone, please.
Thanks in adavance.
:)

Well, I found the culprit/problem.
It was an air vaccum issue. The rubber elbow boot that connects on the opp. side of the pvc valve was cracked. I wish I found it before I installed a brand new maf unit.
I was feeling lazy by not wanting to pull out the shrowd.
What could have been a $13 fix ended up being an $83 fix.
I won't be lazy next time.
cheers!
:)