2 weeks ago my neighbor and I installed Jet-Hot LT’s, Hooker Y-pipe, and Taylor OTVC wires, new spark plugs, new O2 sensors, removed the EGR and Air pump, and did a OBD-I conversion. We took the car for a test ride and it car wasn’t running as it should. This past weekend we hooked the car up to my friend’s scanner and no codes were coming up. I put my OBD-II PCM back in (for scanning purposes) and it showed that cylinders #1 and #8 are misfiring. My friend had an extra set of wires in his garage and we swapped them in and it was still misfiring. I have checked for burnt wires, sensors, etc and can’t find anything wrong. Could it be an injector, vacuum, ect? Does anyone know what might be wrong? I was trying to figure out what the relationship is between #1 and #8 compared to the other cylinders. Why are they singled out and it’s not a widespread problem throughout the others. Maybe that will help narrow the problems down. Any help would be greatly appreciated.

 

try replacing those spark plugs.

 

New ones were installed, all Autolight 104's gapped to .040. They are brand new. I could try it though.

 

I am not a mechanic but couldnt the optispark be bad causing the cylinders to not be getting spark at the right time?

 

When the opti goes bad, is it seen thoughout all the cylinders or can it affect 1 or 2 like in my case. The car has 53,000 miles on it.

 

from what I have seen on here the opti can drop a cylinder or an entire bank.. just depends on what breaks i guess.