Misfire on cyl. 5 and 6

[Al 96 Ram Air T/A]

While doing a few full throttle runs, I detected a surge/misfire at around 5K. It did this several times.

During the last week, I started the car up, and after about 10 minutes, I can hear a distinct misfire.

I just finished installing my dual Interceptor gauges, so now I can see what the computer sees. My misfire counts are high on cylinder 6, and showing up (less so) on cylinder 5.

It becomes more pronounced when the car warms up. I thought about the new Opti, but why would it do this on to cylinders only when the engine warms up?

It's still early in the diagnosis process, but before I waste hours searching, I thought I'd ask. I'm trying to disassemble the interior as my new gauge cluster is being built.

[transamz28]

how old is the opti? could be worn rotor and cap , they get that ash on them after a while, might move a little when warm. and a weak ignition coil can do that i think
IC module ?

[Al 96 Ram Air T/A]

Almost everything (bolt on) is brand new. In all, it has less than 100 miles of use since reassembly.

[Al 96 Ram Air T/A]

I just discovered that pins 5 and 6 are next to each other in the distributor cap...could they be arcing?

[Injuneer]

You go to the possible answer before I could post it. 6 & 5 buttons are adjacent in the cap, and straddle the tower for the coil wire. Check for arcing on the coil wire/tower.

[FTA1995]

Sounds like my old to the T.
Blow into the air input for the opti, It you hear what sounds lke plastic ticking, you might have the same issue. I completely dismounted one of the pins for the number 1 cyl, causing random misfire. I was a really goofy problem until we knew what it was as I was sill getting spark out the no 1 wire, but randomly would have no or weak spark for one rotation, mostly dependant on spark advance.

From what you said, sounds like about 99% its the cap/rotor. The Opti sensor is probably fine.

[AmericanZ28]

Sounds like my old to the T.
Blow into the air input for the opti, It you hear what sounds lke plastic ticking, you might have the same issue. I completely dismounted one of the pins for the number 1 cyl, causing random misfire. I was a really goofy problem until we knew what it was as I was sill getting spark out the no 1 wire, but randomly would have no or weak spark for one rotation, mostly dependant on spark advance.

From what you said, sounds like about 99% its the cap/rotor. The Opti sensor is probably fine.

How do you dismount the pin on the distributor? And how did you fix the problem?