i have a 96 formula m6 has cold air intake, msd opti, full exaust 3in. i belive it has a slight miss when starting off it feels like and at lower rpms when driving. what the firing order? can the opti spark be miss alinged not familar with it?? could the bigger size in exauhst having something to do with it? what the average life span for an opti spark? trying to find someone around me with a scan tool so i know i can do that to find out but was wondering if anyone had any ideas. thanks cody

 

a low RPM miss is easier to track down than a high RPM at least in my opinion.. it usually means you are getting weak spark. At higher RPM more energy is being produced so the spark gets around the bad sport by arching ect. I would change wires/plugs coil first. As far as Opti life span.. my rough guess of an average would be 50 to 70k? There have been posts about ones that have lasted 180k ect. Mine has 100k on it and I think it's just now going out.

 

thanks i changed the plugs and i know that the plugs wires and msd opti were done mid last summer so not to old but the plug for number 5 was really wet with gas and the rest were not. im assuming that was my prob seems to be running better now. could that have been the prob bad plug??

 

If that single plug was wet I would take note of which cylinder it was on. It's possible that you have a bad injector on that cylinder.

 

I see you have edelbrock headers also. That means you have that one plug on the drivers side in the center that is a pain in the @$$.... I feel your pain... still easier than with stock manifolds though.

 

Have you had it scanned? The GM Enhanced Parameters keep a count of the misfires, by individual cylinder.

Courtesy of Shoebox:

http://shbox.com/1/opti.jpg

Yes, it can be misaligned by putting the cam dowel in the wrong hole in the back of the Opti, but the timing would be so far off is probably wouldn't even start. Your MSD has a "timing adjustment" screw, with no index or reference mark. Did you check the screw postion before installing? Again, courtesy of Shoebox:

http://shbox.com/1/opti_back.jpg

No.

Some have failed within a few miles, others have lasted 200,000 miles. The early MSD's had several design problems, and I believe even the latest ones are prone to losing the screws that hold the rotor on. Most people are now using threadlocker on the rotor screws and/or upgrading them before installing.

 

Quick note: My brothers '96 has 205k miles on the original opti. II have roughly 90k on mine despite it getting wet several times.

 

thanks for all the info. i think ill try gettin new injectors which lead me to nest question. what kind should i get and size. what is stock?

 

personally I would replace the one injector where you found the wet plug. I think a single injector is like $60-$90.

 

well how hard is it to change them?

 

It's pretty easy, you take the four bolts up that hold the fuel rail down. Pop it up (use a screw driver to pry it up gently). unplug the injector from the harness. The injector hangs on the fuel rail with a clip, so you just have to work it off. But also.. you probably need to bleed the fuel pressure first. I think I've done this in the past by depressing the valve core at the back of the fuel rail.. Someone might need to correct me on this procedure.. a haynes manual will show you how to do it also..

 

Or a "search".... I know I've posted a fairly detailed injector swap procedure in the past.