Help Needed Missing if reved

[thompson238]

If i rev my truck while in park it acts as if it has what the drag racers call a chatter box ? when it gets above 1500 rpm or so it starts to cut out but if im driving it runs fine above 1500rpm ? any ideas what might cause this? Is this a problem?

 

[JLDickmon]

I really wouldn't think much of it as long as it runs fine under load..

 

[iracemine]

reving increases fuel prices. please dont