Replaced distributer cap and rotor as well as plugs and wires, did not change a thing. Tested for spark from cap and wire and plug all spark is good. Did compression test, all cylinders read at 150 within 3 cranks. Compression is good and spark is good so I’m replacing the injector with the ACDelco mpfi Spider unit and I’m pretty positive this will fix the problem. My only concern is that I can’t afford the new unit for about a week and I have to drive my truck to work and back every day (about 20 mile round trip). Will driving with that cylinder misfiring cause any other problem? The drive-ability hasn’t changed much but the sound makes it very noticeable and I can notice a small power loss as well as it shakes at idle. Is it safe to drive for the next week until I can buy the new injector unit?