need advice. Have a 1999 xjr. Was misfiring and running rough on cylinder 7. changed spark plugs and working fine for about 2 weeks then began to do again. DTC code misfiring on 7. replaced with known good coil and another good spark plug and no change. no oil or water in plug well. confirmed spark by removing and grounding to supercharger. Normal compression. Sea foam added to tank and driven for 30 miles to see if stuck injector and no change. No air leaks found. battery checked and good. can not test injector plug or injector before removing supercharger. Trying to avoid this. if need to be done has anyone replaced injector by removing valve cover? does this give adequate access or not? Can just one side of supercharger be removed or does it have to come out in total? Have not checked current from ECM and not sure how to do from reading jtis. can anyone give instructions. any help appreciated