CODEPO300 RANDOM CYLINDER MISFIRE on 2004 Chevrolet Silverado 1500

HAD LOW COMPRESSION IN CYLINDER SEVEN,HAD VALVES DONE,STILL THE CODE PO300 APPEARS.RINGS OK,NEW PLUGS,WIRES ETC.,NEW INJECTORS,ERASED CODE,CODE RETURNS AFTER @ 3 KEY STARTS.NO OTHER CODES APPEAR. WHAT IS MY NEXT POSSIBLE SOLUTION TO PASS SMOG? THANK YOU

by in La Puente, CA on February 11, 2013
2 answers 6 comments
ANSWER by , February 11, 2013
did you recheck the compression after you did the work?
COMMENT by , February 11, 2013
yes compression is normal in all cylinders now. also fuel line pressure, fuel pump ok
ANSWER by , February 11, 2013
could be anything from primary ign to poss dist is set incorrectly.start by ck'ing dist alignment 1st
COMMENT by , February 11, 2013
ok thank you.could it possibly be a sensor.i.e cam or crank sensor? reason i ask about the sensors is that a cert. mechanic mentioned them to me, and it is relatively costly to replace them on my budget. thanks again
COMMENT by , February 11, 2013
yes but dist alignment is very important and will set codes on 3rd cycle
COMMENT by , February 11, 2013
can you please explain what dist. alignment is,also set codes on 3rd cycle,i would like to relay info, if possible. thank you
COMMENT by , February 11, 2013
set eng to top dead center and point rotor at #1 cyl on dist cap
COMMENT by , February 11, 2013
independent coils.no dist cap. 2004 4.8l 1500.