I'm having a similar issue right now, I'm intermittently losing cylinders 1 and 4. We've already changed coils and blue plate. Every now and then it will start up on all 4 cylinders and run great. Let it sit for 20 minutes and start it again, back on only 2. We've checked all the wiring and everything appears to be making a good connection, nothing changes during the "wiggle test", but sometimes we'll be checking things after it was only running on 2, start it back up after not finding anything again and it will be back on all 4. Any ideas or yet another red box issue?