I just got back from SPEED INC in Shaumburg , Il. I made 2 dyno pulls and had the same " hiccups" both times. They start the run at 3500 and accelerate, at 5200 rpm the power drops off by 60 hp the picks it back up til 6300 then hp drops again. everything is MSD, opti, retard box, 6al, window switch. The tune has the rev limiter set at 7200(pcu) and I have the 7000 chip in the MSD box and develops a miss way before redline. Larry( from SPEED INC) said this is OPTI related and had to abort any further tuning and definitely didn't recommend spraying nos. help?!!

tim jones,
michigan

 

Remove the cap and check the rotor to see if the screws have worked loose.

WD

 

I had the same issue in my car but it turned out I didn't have stiff enough valve springs.

Swapped them out and all is good.

Wouldn't be a bad idea to pull the Opti out and make sure there are no loose or backed out screws. My MSD opti also had rotor screws back right out.

 

Ditto on the loose screws in the opti if you get a chance to check it but I don't think that is your problem since the MSD opti has a type of pin molded into the rotor which keeps it pretty stable in the rotating direction. I suppose if both screws have completely fallen out it could certainly screw things up. Regardless, it is worth checking them...

 

its not valve train, I'm running 8893's and are installed correctly. when I first got the car out , it pulled many 7000 rpm runs

 

I have the same problem with an MSD opti on a 396 LT1. I talked with MSD tech support and after some trouble shooting they decided it was the encoder inside the opti. They are sending me another encoder (for free) and when I tear it apart to install the encoder I'm going to check the screws.

Hopefully that'll get me squared away.

 

talked to MSD first thing this morning and are going to replace it free of charge

 

What are your exact problem symptoms? Typically the optical module either works, or it doesn't and is not RPM sensitive. The module and strobe wheel provides both the high and low-resolution pulses to the PCM. If either are missing, a DTC should be present.

WD

 

I just removed OPTI and removed the cap just to take a peek and sure enough, rotor screws about ready to fall out.

 

Just what I expected from the symptoms you had stated (high RPM miss)!

Have you seen my fix I've posted here of the forum for the loose rotor screw issue (different screws w/ flat washers and thread-locker)? If you can't find that post with a search, PM me and I'll go over the details. The last time I inspected the rotor, everything was perfect with the rotor screws.

WD

 

I just picked up my NEW MSD opti and I called MSD tech to ask about there loc-tite, said they had switched to a new loc-tite and should be good to go, to my curiousity, I checked them, THEY WERE LOOSE!! from the factory, I read engineer's post and did his upgrade right off the bat and recalled MSD tech again to tell them what I found from there factory new and said he would look into it. Goes to show no matter what you do you need to check and recheck to assure yourself. Thanks all for responding to this post.

tim jones,
berrien springs, mi.

 

So, you're using some slightly longer Allen socket-head screws w/ flat washers and red stick thread-locker? Correct! Crank the screws down really good with the Allen wrench and use plenty of thread-locker.

Also, I'm glad to hear you checked the new MSD before you installed it and saved yourself some more pain and suffering. I'm not sure anyone here on the forum has done more Opti removal/replacements then me. I've had so much pain from Optis, I think I'm starting to like pain!

Post or PM me if you have any questions.

WD

 

Hey gusy, new to the site... referred by a fellow f-body friend. I'm running a '94 Formula LT1.

Here's my issue. I've replaced two opti's with a total of no more than 2000 miles (on both combined) in the past month. What's going on? why am I going through opti's like this?

The original Opti was of course, a GM unit, and got me to the 189,000 KM mark (yes, Km, I'm Canadain ) the replacement units have both been reman cores, with MSD cap/rotor kit. (Vented)

I'm thinking there has to be an issue with the core/cap/rotor combo. The last opti LITERALLY lasted about 40 miles, then crapped out just last night.

I'm extremely frustrated, and just want to get this issue taken care of, so I can drive the car and actually enjoy it for a while!

 

Why not buy a new OptiSpark from GMPartsDirect? Is the MSD really worth all the extra hassle and $$ ?>?

 

Remans are a crap shoot. Buy the real GM complete opti.