Ok before I get flamed by anyone I did my homework for 2 days now on "this" site and I've pretty much decided my OPTI is bad. Quick history of my car, since I've had it every time I go through a laser car wash and not even using the under carriage blaster I would get the SES code, this was before longtubes, new plugs and MSD 8.5s, every single time it done this and same thing after the installs. I assumed since it was a 97 with the vented OPTI it would dry out and pretty much did. Also while at the track doing tire heats you could hear it miss sometimes but it ran strong. So I started suspecting the OPTI with 75k miles on my car. For the last two days missing so bad it barely runs. I want to rule out fule management like injectors, etc before I spend 300-400 bucks on an OPTI though.

* INJUNEER - I read your reply today to the guy with the "Opti or Wire" inquiry and I have this to ask you? Well AutoZone scanned my SES codes and got a "multiple engine misfire" and no other code, as in what you mentioned earlier in another post from someone today..."one for the low resolution pulse and one for the high res pulse. If the problem is in the cap/rotor, there are no Opti specific codes to pin it down... you are back to looking at misfires. Just an FYI, in my case I did a good job of installing my 8.5 MSD wires couple weeks back and a couple hours ago I installed a brand new set of AC Delco Platinums (stock replacements). There are no wires touching the JetHot headers, all the boots clicked on the plugs, nice and secure, the opti boots are plugged in fine. Also the new NGK TR55s I removed were just fine (NORMAL burn). Being it's a Multi-Eng misfire could I just replace the cap/rotor you think and be fine? $120 bucks at O'Rielly here in TX. I want to fix it right and if 75k miles is pushing the OPTI then I'll go ahead and change it.

* SHOEBOX - depending on the feedback here I could sure use a website with a good picture howto on replacing the OPTI. I found one once that had a really good layout with details like lining up the crank properly to remove the OPTI, etc. Any tips on sites for this?

Thanks in advance

 

If you are getting misfires and suspect the opti, I would first check every spark plug wire with an ohmmeter. Also, look at the plug wire terminals on the opti for corrosion (you have to look down inside there). Don't forget the coil wire and it's connector.

If you are going to do anything with the opti, I recommend a complete new one from Jason or Dal. With 75k miles, you probably won't get good value from a cap and rotor that costs $120 vs. a complete new unit that is $190-ish. (even though you are not getting optical resolution codes at this point).

There is an opti guide at http://www.streetillusionsracing.com...ll/install.htm

 

I like to rule out the cheap fixes before diving into the Opti. I'll take your word for the plugs and wires (assume that includes the coil wire) being 100%. Some other possibilites:

-IC module (does it get worse when it gets hot?)
-coil
-corroded coil or plug wire terminals on the Opti
-corroded harness connector on the Opti
-corroded Opti test connector on the passenger side of the intake (this always gets mentioned, but I never actually saw one go bad??)
-leaking EGR valve
-plug wire too close or running in parallel with the to Opti harness, RFI throwing off pulse signal

 

my car has a bad miss in moisture too..please let me know if it is the opti..I am going though this also
Brad

 

Man this site rocks...ok Injuneer my replies to your bullets below:

I can't thank everyone enough, my urgency is that I HAVE to pick up my son 2 hours away tomorrow and I have to get it fixed ASAP tomorrow after work...thanks again.

Appreciate the info Shoe