It would help to know why you replaced the coil in the first place. If you replaced the coil simply because you weren't getting spark, you may have made a mistake. The TFI module seems to be the #1 culprit for EFI 5.0's not getting spark. Test the coil. If the coil is good, I wouldn't hesitate to replace the TFI module right away; it's the thing bolted to the front of your distributor. Chances are you will need the special TFI removal tool to get the little bolts out (parts store guy will know what you're talking about). Good luck.