It idles too high... sometimes. It's as if the computer is hunting for an idle. Goes between 900-1500 rpm. Mine was the first one that the pump guy had that acted like that. He's seen 1 since that did it. Something in the programming of the '99 truck doesn't digest well with the pump. Dealer reflash "will fix it"... hopefully. I've been having programming problems with truck since I have it. Maybe I should just p-pump it an run!?!
A Smarty would have the latest dealer SW I would think.
Jim