so, my car presents with a drivability problem. when given gas it will stumble and bog, initially. I did a fuel pressure test.(before new wix fuel filter and after,the new filter was worth 3 lbs in) and found it holds 45 or so lbs.in. indefinitely after you shut it off,running it is 35-38 lbs in.when given gas from idle it drops to 30 or so then goes to near 50 before settling down to 35-38 at idle. I have a FSM and I followed the trouble tree .but everything checks out?? it runs with the CEL off and there are no codes stored.the engine is newly rebuilt and all components are new?? the exhaust smells slightly rich,but MPGs are 20-25!! man I am asking ,does any one have any insight?? oh,yeah.its a 86 TPI 305 bone stock Camaro. also I did a vaccum leak check all over the motor with starting fluid.no change .so I feel it has no vaccum leaks