Ok, I have a miss, or more like a stumble around 5500rpm. Before we jump on an opti related bandwagon, it was replaced about 5000 mile ago along with a tune up. I was thinking it may be the coil?? What would be a good upgraded coil??? Thanks

 

Don't even think about doing anything else without checking your coil. This topic doesnt deserve a new thread..., I had same EXACT problem as you, it was a corroded/bad coil.

There were many threads that were just like this one... just use the search feature.

 

i 2nd that!! even before you change the coil pack, try the coil wire...be generous with the dielectric grease.

--mj

 

Coil, Coil wire, if that dont fix it then back to the opti.

I had the same problem and it tured out to be a combination of all the above.

Jason Coffman

 

Check the coil/coil wire. I had the EXACT same problem and it was the coil wire. Check my site in the sig and you'll see what I mean.

 

i would get the factory coil. when i went through this, i found out that the msd and accell coils had more problems than the delco coil. i have not had any problems with it to this point in time.

 

advance auto coil=$25/30

I had MSD 8.5 MM SD spark plug wires and the fool who put them in did NOT put the coil wire on. I called MSD, told them the situation, and they sent me a coil wire for FREE! Replaced it, ran it about 10 miles, then tried a WOT run and it ran great, no more miss.

I had the wires, plugs, and coil replaced and when I replaced the coil, I noticed the stock coil wire and became to think (didn't MSD send me 10 wires? and I'm only using 8). With my year Z28 they have two coil wire applications so they send two coil wires.

After a great conversation with the guy at MSD, he sent me a coil wire (actually two) to my house for free, took about a week, and now my car is fine.

my 2 cents, replace the coil wire AND the coil. Your total cost should be UNDER $35-40 for both. plus about 30 minute installation on both.

 

Could be spark plugs too. When I hit 60k on my car I had my plugs changed, but we couldn't get #2 out. A few weeks ago my car started losing a lot of power above 5000rpm in 2nd. Since I'm of the belief that not every single performance problem in the LT1 is Opti related, I decided to first get that plug changed. So after paying a GM dealer an insane amount of money to change one spark plug for me, my power is now restored, it pulls strongly to the redline again. It's also possible that the fuel filter change I had them do helped, although the fuel filter on there wasn't that old, so I'm 95% sure that bad spark plug was causing the problem. It looked pretty nasty when they pulled it out, the gap was more than .080, as the platinum was totally gone. Makes me laugh too, the car only has 83k on it, so how does GM actually think those things will make it to 100k? Not a chance.