Misfiring after ECU fix and spark plug changes

[liybzd]

Hello, I had a bad misfire a couple of months ago, one bank was totally gone, I replaced the ECU caps according to the suggestion by some forum members and the car ran good for a couple of days after that. A few days later, it started to misfire again on cylinder 6 and 8, so I replaced the spark plugs hoping it will go away, and it did for a while, although I always felt that it's not running right, e.g. vibration at idle and speed over 50(which could be a wheel issue, but I don't remember it happened before the incident). 

Last night it happened again, the code pointed to cylinder 6, but I felt it's more than that, since it was as violent as the first time when the engine lost 4 cylinders. I was suspecting the distributor, I don't know it's condition. The car is a 96 and just past 200k. Please provide any other opinions/ideas on this issue, thanks!

[vissine]

I would to the spark test but before that want to check the vacuum lines. The fuel quality maybe a problem too.

[sha4000]

With that many miles I would just change the distributor just to be sure before 

[gymguy]

Just a wild guess. Two years ago I fixed the ECU (new caps) and did a general timing belt, water pump replacement, plugs, etc on my '94 LS400. My wife limped home one day in our '94 recently.. It was running very rough (sounded like only four cylinders) and smell of gas let me know that this probably wasn't ECU or plugs. Did some diagnostics and found I could fire plugs on one bank of 4 cylinders but not the other bank. I tested primary and secondary resistances on the ignition coil on the bad side. The coil was open. I was able to get a new one (in stock) from Advance Auto or AutoZone...can't remember which. Replacing it was not fun but it has been running for 2 months now...no problems. Check your coils.