over fueling

i have a 1994 chevy blazer v6 vortec 4.3l. It is overfueling at idle and it smells of fuel. it also shakes when it is in idle. i put in new plugs and a coolant sensor, help some but it is still overfueling. Any advice would be much appreicated.

does it do it when it's cold & and hot?, have you checked air filter ? does
it have orig. O2 senser? have you checked to see if all vac. hose's are
connected & in good shape..

Runs rich...hard starting?
W engine series?
Then, this sounds like CPI and/or internal fuel lines leaking...sorry to break the news to you...