i had a number 2 cylinder miss that i could not figure out. i swapped injectors, new plugs, boots, all new igniton set up. it would come and go, hot or cold. run good one minute the next rough idle no power. this is on a rebuilt 2.4 with only 9,000 miles
here is the link http://www.j-body.org/forums/read.php?f=11&i=152223&t=152223

i did a compression test and had 0 on the #2 cylinder. so i figured a sticky valve because it would run great full power then not so much the next. i tried seafoam to clean the engine to hopfully unstick the valve. went to my friends house to try to run some more in the engine and out of nowhere it reved to 3,500 rpm and quit. tried to start it and and turned over and tried again and it made a bad noise. so call my friend up and he tows me to his shop. i start pulling the motor apart and found the proplem on my 9,000 mile rebuilt motor. the head i got from cylinder heads international on ebay , the seats came out! all 3 valve seats where on the way out and the 4th is the one that fell out and smashed my piston all to hell. the #3 cylinder also has damage to the pistion from those valve seats starting to come out! so now i have a 9,000 mile rebuilt 2.4 with a messed up head and 2 really damaged pistions. i mite need a bore and i hope i didnt bend a rod. i called CHI and they will send me a new head but that dont really matter because i have to pull the motor AGAIN, and spend more $$$ and i dont have another car to drive. this sucks. im sure when a place like CHI do heads all day long they have a bad one everynow and then but this dont help me any! i got way to much in this car to just junk it so im gonna redo it AGAIN