I just had my entire fuel system replaced (CP4 Failure). I now have a horrible low idle lope. I'm taking it back to the shop soon but would like to have an idea of what I'm up against. It doesnt matter whether its cold or at operating temp. At idle it will randomly start loping. Sometimes so bad that it wants to kill over. The second I give it the slightest amount of throttle it clears up. Any ideas?