hey i recently had a new distributer put in by a mech. and when i got my 85 sierra back (350) it ran with the new distributer but the check engine light came on when accelarating and when doing this it sometimes backfires and stuters. but when up to speed it runs fine. i bought a vacum gauge ( damn there more then i thought) and hooked it up to the pcv. it came out to be 3" at idel and and would go anywhere from 3 to 5 when giving it gas. i pulled out the vacum diagram and checked that all the hoses where hooked up corectly and not broken. according to what i have read about vacum gauges the reading i am getting says to check all hose hook ups and that there not broken. any ideas? ive told the mech. that put my new distributer in what has happened and he told me to do what i have already done. BTW- there is a small but steady fuel leak from the gas line going directly into the carb, not sure if that would be directly related to my symtoms.