Yesterday, I was driving around with one of the moderators here, everything was great and then we stopped at a light, at which point I turned to him and said, something is wrong. Long story short, it felt like a mis-fire under 3k RPM.

I had a set of plugs and wires at home, so I went there and grabbed them, we put them in yesterday and it's still doing it. So I figured fine, my MSD Blaster coil is probably shot, there was a stock one lying around, so I put it in, and I'm still having the same problem.

I 'found' an ICM, I tried putting it in. But it threw a code (didn't bother checking the code), and the car ran the same way as it did with the original one. Then I checked the part #'s and they are different. The 'found' one is [799 8C19], the original one is in the car and to much of a pain to read with the coil on it. (Anyone know the correct part #?)

The opti is under a year old. And it was sunny/warm out at the time, so it didn't get wet half-way through the drive. I have an MSD 6A box on the car.

I guess I could bypass my MSD box, to see if that helps, but I have my electric water pump wired into the same circuit so it's a pain to do. Any other suggestions?

 

I broke the exhaust valve spring on #1... if anyone's interested.

 

and at what RPM did you do that

 

Hard to say, maybe 5.5k. But I didn't notice it for a mile or two after that, so I'm assuming it happened then. Thing is, these valve springs should have been fine with my CC305, they're the ones that came with my MTI LT4 heads.

Does anyone know what kind of valve springs would have come on them? I emailed MTI, I'm trying to figure out if they are stock diameter or something else.

 

You should also check and see if they will warranty the valve spring(s). 5500 is not that tough on most valve springs.