Another test which my mechanic did with me in the car was...
He placed the car in 1st....got in moving (slow speed) and then dropped it 4th...causing a real load difference on the car and he could hear a faint "popping" noise which he said was that the car was backfiring - but thru the air intake. Which meant 2 things....a cylinder isn't firing or its' running too lean.
But the other guy asked a good question - did you replace the wires?
GO BABY GO! 
