My 2012 Ram 1500 has 110000 miles on it and recently had thrown a P0305 code for cylinder #5 misfire. It runs rough, lack of power, fuel economy went to crap. I had a compression check on the cylinder and it was good (150 psi - comparable to the other cylinders), checked the coils and spark plugs (they are all good) checked fuel injector resistance (running 13.2 ohms with other injectors running 13.2 to 13.5 ohms) ... could be a clogged fuel injector, I suppose but I have run seafoam in both fuel and oil, and still having issue. I have no idea what to check next. Anyone have a similar issue with a misfire condition and could not find anything wrong with cylinder or fuel injection system?

Markt.2015 in Nebraska
Happy Ram owner since 2004

 

See if you are getting injector pulse on number 5. Should be able to rent the noid light for testing. (either that, or simply test in the parts store parking lot..... it's quick and easy.)
Swap the injector with another one. (cylinder 3 or 7) See if the miss moves with the injector.

 

Thanks HeyYou .... I should have told you that I used noids on cylinder 8, 6, 3 and 5 .... all 4 cylinders had good pulses. Not sure what to do next, but I have read on some other sites that it could be the valve spring. Have you heard that about the Hemi 5.7L having issues with valve springs?

 

Swap the injectors around, and see if the miss follows the injector. May just be dirty/clogged.