99 Chevy z71, has a hiccup. please help.

blueeyedfrog

Ok, over last summer both heads cranked. So we rebuilt the motor all the way down to the lifters. Took it in to a friends shop to time it with the scan tool, it at-0, so darn near perfect. The issues is after all this work, it hick ups and eats the hell out of gas. No pattern to it sometimes it does it more then others. No codes. I took it up to the college to put it on the dino, it only does it while driving. When it cuts out, #3 drops out. I've changed the plugs and wires, distributor, and recently the fuel pump and filter. Any other advise out there. 

Mr_Shiftright

Sticking valve? You might run a compression test on #3 and see if it's irregular.