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'96 Opti questions

354RwHpLT4CE

Well-known member
Joined
Oct 14, 2003
Messages
120
Location
Memphis,TN
Corvette
1996 LT4 CE Coupe
Hey fellas,My opti's starting to show me signs of failure(slow to start,high rpm sputter).I am curious if anyone has had any luck cleaning their opti and replacing the cap and rotor(MSD likely)to cure these early warning signs.(Assuming the bearings and other parts are still ok).Just wanting to save some cash if I can.Otherwise I will probably replace it with the new Billet MSD unit.I know its a gamble,but I am tearing it down to replace a rear leaking intake gasket anyway.All input concerning this issue will be appreciated.(especially if you have the new MSD unit.):)
 

Notorious

Well-known member
Joined
Oct 9, 2005
Messages
53
Location
Confederate States of America
Corvette
Highly modified '95 A4 coupe
I've heard of folks having some success with cleaning and a new cap and rotor on the early opti. No reason it might not help on the later one either. The only way to really know is to remove the cap and see. They are sealed much better though and should be less prone to these problems and also due to the venting of course. And to anyone with a vented opti, check the hoses down at the distributor. I've seen them rot and come off due to oil contamination of the vacuum hoses. If this happens, moisture and dirt can enter the distributor. When you reseal your intake, I'd recommend Permatex's 'The Right Stuff.' It's much better than silicone and will cure the intake end seal problem once and for all.
 

354RwHpLT4CE

Well-known member
Joined
Oct 14, 2003
Messages
120
Location
Memphis,TN
Corvette
1996 LT4 CE Coupe
opti issues

Thanks for the reply Notorious.Yeah,I keep a couple of cans of "The Right Stuff" around because it works so well.Still use the original permatex for sealing head gaskets around coolant passage holes too.;). I would still love to hear from some more people with experience on the Optispark issue.Should I spend the 200$ for the cap and rotor,and just clean it,or just plunk down the 500$ for the MSD?Tearing it down again in six months or a year because of the same symptoms wont bother me,but tearing it down again in 3 months because it left me stranded will.All opinions welcome.:v
Notorious, Did you go with a kit for your stroker motor(bottom end) or did you piece it together?And whats it run in the 1/4 now?(wow,I just hijacked my own thread,am I A.D.D. or what.)
 

Hrtbeat1

Well-known member
Joined
Nov 24, 2002
Messages
923
Location
MS Gulf Coast
Corvette
'90 coupe (gone) '96 CE LT4 Z51
I've got occasional issues with my Opti as well. Just the random break up at higher RPM's. I can't seem to get it to do it when I'm scanning but I do occasionally get the break up. One time was on my first dyno run. It shows up pretty clearly in the printout. I thought it might just be the plugs and wires, which I changed. My next trip to the dyno I had about 6 runs and it showed its ugly head again.

I sprang for the MSD billet Opti, but haven't installed it as of yet. I've been waiting till I do the cam swap (which is also on the shelf in the box.) Other priorities have kept me from spending the time doing mods. Hopefully I will be able to get back to the mods soon though.

:w

:pat
 

Notorious

Well-known member
Joined
Oct 9, 2005
Messages
53
Location
Confederate States of America
Corvette
Highly modified '95 A4 coupe
Thanks for the reply Notorious.Yeah,I keep a couple of cans of "The Right Stuff" around because it works so well.Still use the original permatex for sealing head gaskets around coolant passage holes too.;). I would still love to hear from some more people with experience on the Optispark issue.Should I spend the 200$ for the cap and rotor,and just clean it,or just plunk down the 500$ for the MSD?Tearing it down again in six months or a year because of the same symptoms wont bother me,but tearing it down again in 3 months because it left me stranded will.All opinions welcome.:v
Notorious, Did you go with a kit for your stroker motor(bottom end) or did you piece it together?And whats it run in the 1/4 now?(wow,I just hijacked my own thread,am I A.D.D. or what.)
$200 for a cap and rotor? Is that OEM full dealership price? Even the MSD OEM replacements aren't anywhere near that much. If you're concerned, I'd look underneath it and then make your decision.
I guess if anyone's allowed to hijack a thread, it should be the OP. :L
My stroker parts are hand selected and the particular combination is a bit unique in a couple of respects. So far, suffice to say that ETs have been very encouraging. W/O my best converter currently installed and in dire need of better DRs than the Nittos, it's running 7.90s in the 1/8th. This is with 3.07 gears too, so you might say that in effect, I'm running a Powerglide! ;)
 

354RwHpLT4CE

Well-known member
Joined
Oct 14, 2003
Messages
120
Location
Memphis,TN
Corvette
1996 LT4 CE Coupe
$200 for a cap and rotor? Is that OEM full dealership price? Even the MSD OEM replacements aren't anywhere near that much. If you're concerned, I'd look underneath it and then make your decision.
I guess 200 is slightly exaggerated,ebay has them for 154.00 BIN(MSD).My only issue is the car is my daily driver,I have another vehicle, but my wife drives it.So my out of service time for the vette has to be kept to a minimum.(i.e. I need the parts in hand before teardown on the weekend.At this point,I am leaning towards the Billet MSD for both cost reasons(the Delteq,the Dynaspark,the LTCC when all said and done would be between 600-800$ and an OEM is between 170-400$)and durability.After more research,I am seeing it wouldnt be beneficial to just do the cap and rotor,as I could just replace it with an OEM unit for about the same price.So I guess unless someone talks me out of buying the MSD,and spending the extra money on the Dynaspark,thats where I am headed.:w
 

Ruby Fan

Well-known member
Joined
Oct 7, 2004
Messages
189
Location
NY
Corvette
1985 Black Beauty Coupe, 93 Ruby, 96 CE vert
I did an opti-spark change on my '93. Had to convert the cap to a '96 for better venting. If you get down to the point of taking the dist. off, just replace the whole works. Mine showed corrosion at 21K.
 
T

Topless_Ruby

Guest
I did an opti-spark change on my '93. Had to convert the cap to a '96 for better venting. If you get down to the point of taking the dist. off, just replace the whole works. Mine showed corrosion at 21K.

I also have a 93, Is there any kind of PM that can be done to prevent the problem?

Does the 96 cap fit the 93 and what is needed to "convert" it?
TR
 

Ruby Fan

Well-known member
Joined
Oct 7, 2004
Messages
189
Location
NY
Corvette
1985 Black Beauty Coupe, 93 Ruby, 96 CE vert
The '96 cap will fit the '93, but you will have to plug up a vent hole on the dist. with something like JD Weld putty. Then you would have to get a GM venting set-up part from a '96, which you attach to the dist.(can order that from GM-$16) then plug(fit) on end into the air runner, the other tube end into the breather tube(grommet). You would have to get a breather tube that accepts both vent hose and stock breather hoses. a cheap part at any auto store.(a standard GM fit all). Not that bad of a job to do, the hardest part is to get a REVERSE torx socket($20) to take apart the dist. cap. I believe it is size '4', that you would get from SnapOn. So far everything is working well. Corvette Fever had a detail article on how to do this job. The balancer would have to come off, pretty easy, just pry around. You need a '93 dist., and a '96 dist cap. The dist. are not interchangeable, because of different cam tooth. If you like to tinker, you can do the job. Hope this helps
 

Notorious

Well-known member
Joined
Oct 9, 2005
Messages
53
Location
Confederate States of America
Corvette
Highly modified '95 A4 coupe
My OEM replacement has not quite 30K miles on it so far. So hopefully it'll be awhile yet. But when it eventually needs replacement, at this point my choice would be the MSD unit too. From all I've read about it's design, such as heavier bearings for longer life and more high RPM stability as well as other internal improvements over even the later factory units, I think they've done their homework. The much cheaper Accel opti replacement is a joke by comparison. But then I've never been impressed by Accel's electrical and electronic products, so I'm not surprised.
 
L

Louis Bartay

Guest
The Corvette shop that rebuilt my LT4 just used a AC Delco Cap Kit (about $165.00) and made sure the vacuum line to the intake was in good shape. All is just fine 6000 miles later. They did use sealer on the gasket (good insurance).

On my wife's LT1 WS6 TA I had the whole opti replaced with a new water pump and plug wires (one bad plug wire will kill a opti fast) at 130,000 miles. I have see some horror posts on the opti units being POS. I have been lucky.
 

aboatguy

Well-known member
Joined
Jul 1, 2005
Messages
424
Location
Slidell Louisiana
Corvette
AI head/cam/intake, Vig converter, D44, EM LTs etc
Thanks for the reply Notorious.Yeah,I keep a couple of cans of "The Right Stuff" around because it works so well.Still use the original permatex for sealing head gaskets around coolant passage holes too.;). I would still love to hear from some more people with experience on the Optispark issue.Should I spend the 200$ for the cap and rotor,and just clean it,or just plunk down the 500$ for the MSD?Tearing it down again in six months or a year because of the same symptoms wont bother me,but tearing it down again in 3 months because it left me stranded will.All opinions welcome.:v
Notorious, Did you go with a kit for your stroker motor(bottom end) or did you piece it together?And whats it run in the 1/4 now?(wow,I just hijacked my own thread,am I A.D.D. or what.)
I'd spring for the 225 GM replacement opti (if you search ebay a couple of them show up every couple of weeks. ) The one I bought was from the Partsladi and it was new in a GM box(about 240 delivered). I've read on a different sight that there is a cheaper source right now!



I'm a "THE RIGHT STUFF" fan too!
Mike
 
L

Louis Bartay

Guest
The only problem I have witha Great deal on ebay is a lot of New opti sparks were defective from the factory. If you are not gonig to use a rebuild kit from AC/Delco just buy a new one you can return from a local shop.Better to pay a little more now than gamble on a ebay part, but sometimes you will get lucky and get a good one on ebay. Electric parts are something I would not buy from ebay just for this reason.
 

LT4man

Well-known member
Joined
Jun 25, 2003
Messages
2,214
Location
Chicago
Corvette
96 Collectors Edition LT4
I also encountered a high rpm miss when my LT4 was very young. I installed an Accel 300+ ignition box. No more high rpm miss.

When I accumulated almost 90,000 miles I was getting ready to drive to CF IV in Colorado Springs from Chicago. I did the following:

Investigated all the Opti and cap & rotor options. Because of the mileage, I decided to just replace the cap & rotor. Optis are designed to last between 150-200,000 miles.

The Accel cap & rotor from Summit Racing is $99.95. The kit comes with two (2) gaskets made out of some sort of rubber (silicone?) which gives you a water-tight seal between the cap & the intermediate plate and the intermediate plate & the main body of the Opti.

When I disassembled my cap, I found the two (2) screws responsible for holding the rotor on at the bottom of the distributor. My engine was still running, albeit with a noticeable lope in its idle. More of a lope than I was accustomed to. I put the new rotor on (tightened those rotor screws really well) along with the cap.

When I finished the job, the engine started SO FAST, I thought it was gonna jump out of the cradle. Went to CF IV and averaged over 28 miles to the gallon. Engine runs better than when it was new.

SAVE THE :w
 

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