Some body else with a missfire

[Inkertinker]

OK, I have a miss that appears after I have been driving for about 15-20 minutes. The engine will be running smooth at 1600-2100 on the tach, if accelerate a little or go up a steady incline it will start to miss. The longer I drive the worse it gets.

What I "Know" so far; (or think I know about my 97 SHO)
1. Cams are welded
2. Problem appears sooner the warmer the weather
3. EGR is good
4. Fuel filter, pump, and fuel pressure good
5. During acceleration bank 1 is lean (while engine is missing) Thanks, James
6. Secondaries are working properly
7. No codes
8. MAF is clean, K&N panel installed 8k ago
9. Intake and runners saw 7 cans of Berryman's 8k ago
10. Wiring harness for the engine is from a 96, my car is a 97, (old one toast) it was heat shielded when I installed it.

I have 4 new COPs to install and I sent a set of 8 injectors out to be cleaned I plan installing these parts ASAP, I guess I want to know if there is anything else I should do or look for while I'm doing this? I would hate to take the intake off and still have the miss after I'm done because I did not do something else while I was in there. The idea that it is heat related is still nagging at me.
Thanks, Dave

 

[Mr Anonymous]

It's a bad coil. Fails as it heats up, seen it a zillion times.

 

[Ian Macoomb]

But it doesn't sound like it's missing at idle. I've never had a bad coil that wasn't most noticeable at idle. Sounds a bit like torque converter shudder.

Oh and you really should call Ryan back. Jihad on you.

 

[Inkertinker]

The transmission was replaced by the previous owner 45k miles ago with a Jasper transmission, I would think the torque converter was replaced then, but I do not know for sure. I was hoping it was a coil, but knowing that there is a heat issue with these cars, I was not sure if the coil would become less reliable the hotter it got or if would just fail completely.
Thanks, Dave

 

[SHOZ123]

Buy four new ones and put them in the back. Then you can play the guessing game up front with extra coils if the miss is still there. Very carefully examine for cracks in the coil hard plastic body usually under the connector. This is a common failure point on the coils I have laying around.

I heard about somewhere that some silicone grease on the boot will help too.

 

[Inkertinker]

I put in 4 new coils in the back, I also replaced the leaky cam cover gasket, pulled the plugs just to look and #1 was covered with oil. (a leak I did not know about) I put in 4 new plugs, new cam cover gaskets front and back, refreshed injectors and I hope it works.

 

[Inkertinker]

Looking good

I drove from St Louis to Indianapolis and back twice last week not a miss to be found, Life is good.