1992 Lexus sc400

[sparky 92]

I have a 1992 sc 400 that I am having running issues with. I think that this is an electrical issue. sometimes she runs great on all 8.I have replaced both coils. I will start her up and drive her a few miles and then she runs like crap. I am thinking that it may be the igniter? Is there a test that can be done to check that? I appreciate any help that I get on the matter. Thank you sparky92