2001 Blazer V-6, 4.3l, 113,000 mileage. After trip through the mountains, got a flashing service light, reset after normal drive, no change noted in performance - mechanic found misfire code on cylinder 4. New plug, wires and distributor cap. Flashing light returned, 'sea-foamed' the system and seemed to correct. After additional road trip, flashing light return and went solid. This time at idle, engine running rough, check of code still showing a misfire on cylinder 4. Added fuel injector cleaner to engine, minimal improvement, service light still solid. Tested fuel line pressure, showing 55, no drop-off in pressure....Haynes Manual says is okay but this forum mention it should be 60+ ?? Fuel pump was replaced about 2 years ago. Should I change out cylinder 4's injector since it seems to be isolated to that cylinder or is there something else I can check or might explain this issue. Thanks in advance for any input.

 

I had the same problem recently, i found the misfiring cylinder, and took the whole injector unit out. Then i just put an air hose to the clogged jet and blew air into it a couple times and it worked great after that, lol