C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Optispark??? Too many Options!!!

Thread Tools
 
Search this Thread
 
Old Dec 6, 2008 | 09:01 PM
  #1  
psd_bullitt's Avatar
psd_bullitt
Thread Starter
Instructor
 
Joined: Jan 2008
Posts: 245
Likes: 0
From: McKinney Texas
Default Optispark??? Too many Options!!!

Here are the symptoms:
The check engine light occasionally came on and codes would say random misfire but after a while it would go off on its own and there wasn’t any noticeable misfire or power loss. It would stay off for long periods of time and I didn’t notice any issues. Well driving to work a week ago it came on again but I didn’t fret too much. On the way home however it started to Flash (I’ve never heard of a flashing check engine light) and I noticed loss of power. It was knocking and running a little rough. I was almost home so I just babied it a few miles but by the time I was home it was definitely missing on several cylinders and running rough. Only code is random misfire.

I’m guessing it is ignition related and probably the Optispark Distributor as it has fuel pressure and MAF is clean and voltage is normal.

I’m having it towed to Corvettes of Dallas to check it out for me. I hope it is something simple. A friend says it sounds like the distributor but COD will diagonose it completely. The tech recommends an MSD Distributer over the GM if it is actually bad. I’ve read so many different threads about the Opti that my brain is fried. The original GM part has lasted at least 12 years so I can’t fault them too badly though it is an obvious design flaw putting it directly below the water pump. My pump does not appear to be leaking though.

Anyway, I’ve done some comparison price shopping on the web and found many options: There are probably many others but these range from $250 to $600. Is a $600 Dynaspark or $469 MSD really that much better than a cheaper brand like Accell, Jegs, or Delphi???

Corvette Forum Store:
Delco 95-96 OPTI SPARK DISTRIBUTOR
Product Number:M-3694 Price: $399.00

Delphi 95-96 OPTI SPARK DISTRIBUTOR
Product Number:M-3857 Price: $269.95

Ecklers:
MSD Performance Distributor Assembly, LT1/LT4, 1995-1996
Item# 51875 Price: $469.99 ea.

Accel LT1 Ultra Optispark II Distributor
Item# 59125 - Price: $299.99

JEGS
LT1/LT4 Distributor w/Vented Pin Drive
Item# 555-40011 Price: $249.99

Dynaspark.net
Dynaspark Distributor Gen II
LT1/LT4/L99 - Price: $599.99



EDIT:
Good News / Bad News:

Good News is that it is not the Opti Spark.

Bad News is they said I have a bad fuel injector in Cylinder 7 that was stuck open and has filled it with fuel. They recommend a complete set of new injectors instead of just replacing the single bad one. Justification is they are all now ~13 years old so I might as well take care of all 8 injectors now. Accel injector set ~$360 plus labor. They say the 26lb injectors are more then adequate for my mods and that there is still room for some growth. If I wanted to upgrade to a heavier flow injector I'd need to get it retuned. Ultimately I would make more upgrades if I was keeping the car but for now I guess I'll just go with stock size.

They also recommend replacing all the Spark Plugs but the wires are fine.

Thanks for the input on Optisparks. I guess its good news that I get to spend a little less money the I thought!!!

Last edited by psd_bullitt; Dec 10, 2008 at 05:14 PM.
Reply
Old Dec 6, 2008 | 10:57 PM
  #2  
grinditout's Avatar
grinditout
Drifting
10 Year Member
 
Joined: Jan 2008
Posts: 1,677
Likes: 11
From: Macon Georgia
Default

I have have had all three in my hand, I have a Dynaspark on my car.
Reply
Old Dec 6, 2008 | 11:10 PM
  #3  
STL94LT1's Avatar
STL94LT1
Race Director
20 Year Member
Conversation Starter
All Eyes On Me
Liked
 
Joined: Jan 2002
Posts: 12,261
Likes: 85
From: O'Fallon Missouri
Default

I would stick with the GM replacement opti. You can pick one up from "thepartslady" on ebay for $245. I've seen too many problems with aftermarket units.

http://cgi.ebay.com/ebaymotors/95-96...Q5fAccessories

Normally when an opti is going bad it will throw a code. Since you have no codes present, I would check the crank position sensor first.

FYI: Don't drive a car far that is displaying a flashing SES. It could cause some serious damage to the engine or cats. A steady SES light is fine to drive on, it is just an emissions code.


-Mike
Reply
Old Dec 7, 2008 | 12:25 AM
  #4  
Redeasysport's Avatar
Redeasysport
Le Mans Master
 
Joined: Dec 2004
Posts: 5,789
Likes: 8
From: Myrtle Beach SC
St. Jude Donor '05-'06
Default

Stay away from Accel haven't read too much good about them. IMHO the order of quality is
1.Dynaspark
2.MSD
3.OEM

That being said on your year you already have the improved opti and there is nothing wrong with it. Have your wrench put a good seal of "The Right Stuff" around the cap and put a hose on the WP (which you should change with the opti anyway) and you should be good for a loooong time.By the way Delphi and Delco are the same OEM units Dephi is newer manufacturing date.As stated thepartsladi sells OEM units. The Dynaspark is superior to the rest because it comes totally sealed with bearings(instead of OEM bushings) for the rotor and riveted rotor to prevent the rotor from coming off. The MSD is similar but you have to install the rotor with screws and put the cap on yourself. There have been reported issues with MSD rotors falling off possibly by bad install.


Last edited by Redeasysport; Dec 7, 2008 at 12:35 AM.
Reply
Old Dec 7, 2008 | 01:28 AM
  #5  
Kinkajou's Avatar
Kinkajou
Burning Brakes
10 Year Member
 
Joined: Apr 2005
Posts: 1,109
Likes: 2
Default

I replaced my optisapark with an OEM from the partslady, but it failed at about 200 miles.
Rotor exploded. I thought that OEM was enough and I could save some bucks.
Wrong decision. I then used other system, can not remember the name but used a coil per cylinder. They had great customer service but did not work with my 94.

So I did what was needed in the first place. I got a Dynaspark. It has been the best money spent in my vette, it works great and is really waterproof.
It is a great investment considering the peace of mind it gives.

And by the way I saved a lot of bucks learning to change the opti myself wich would be a good option for everybody.

Good luck!
Reply
Old Dec 7, 2008 | 09:47 AM
  #6  
M. Schumacher's Avatar
M. Schumacher
Pro
 
Joined: Jun 2008
Posts: 610
Likes: 1
Default

The check engine light occasionally came on and codes would say random misfire but after a while it would go off on its own and there wasn’t any noticeable misfire or power loss.
I narrowed down a similar problem to one cylinder by driving around with a code puller connected. Mine would get progressively worse as it warmed up. By reading the code immediately upon the light coming on I consistently got a cylinder six misfire instead of random misfire. It was a bad spark plug.
Reply
Old Dec 7, 2008 | 10:08 AM
  #7  
MikeC4's Avatar
MikeC4
Melting Slicks
 
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
Default

Originally Posted by Kinkajou
I replaced my optisapark with an OEM from the partslady, but it failed at about 200 miles.
Rotor exploded. I thought that OEM was enough and I could save some bucks.
Wrong decision. I then used other system, can not remember the name but used a coil per cylinder. They had great customer service but did not work with my 94.

So I did what was needed in the first place. I got a Dynaspark. It has been the best money spent in my vette, it works great and is really waterproof.
It is a great investment considering the peace of mind it gives.

And by the way I saved a lot of bucks learning to change the opti myself wich would be a good option for everybody.

Good luck!
Regarding the OEM, that seems unusual that the rotor would explode after only 200 miles. Do you run at sustained high RPM's ??

Reply
Old Dec 7, 2008 | 11:51 AM
  #8  
BrianCunningham's Avatar
BrianCunningham
Team Owner
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Mar 2001
Posts: 30,845
Likes: 293
From: Boston, Dallas, Detroit, SoCal, back to Boston MA
Default

You might get by with just a cap & rotor.
I did mine at 110k, I've got 140k on it now.

Dismantle it and have a look.

So far so good on my stock rotor & cap keeping together at the track.
Stock rev limiter setting though.

I bought an MSD for the new engine.

If you choose to buy one, take the cap off and put some locktight on the rotor, some have been loosing thier rotor at the track.

Originally Posted by Redeasysport
Good call on the weep line.
I'm going back to a mechanical WP, I've got an electric on it now.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-1

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-2

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-3

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-4

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-5

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-6

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-7

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-8

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
story-9

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
Old Dec 7, 2008 | 12:05 PM
  #9  
pr0zac's Avatar
pr0zac
Melting Slicks
15 Year Member
 
Joined: Mar 2004
Posts: 2,141
Likes: 2
From: Pittsburgh Pa
Default

tpiparts.net sells them cheap. i would do a gm or dynaspark. too much hear-say with the other brands for me to go with them. haven't really had a problem with gm ones that i haven't messed up from my own stupidity.
Reply
Old Dec 10, 2008 | 05:13 PM
  #10  
psd_bullitt's Avatar
psd_bullitt
Thread Starter
Instructor
 
Joined: Jan 2008
Posts: 245
Likes: 0
From: McKinney Texas
Default

Good News / Bad News:

Good News is that it is not the Opti Spark.

Bad News is they said I have a bad fuel injector in Cylinder 7 that was stuck open and has filled it with fuel. They recommend a complete set of new injectors instead of just replacing the single bad one. Justification is they are all now ~13 years old so I might as well take care of all 8 injectors now. Accel injector set ~$360 plus labor. They say the 26lb injectors are more then adequate for my mods and that there is still room for some growth. If I wanted to upgrade to a heavier flow injector I'd need to get it retuned. Ultimately I would make more upgrades if I was keeping the car but for now I guess I'll just go with stock size.

They also recommend replacing all the Spark Plugs but the wires are fine.

Thanks for the input on Optisparks. I guess its good news that I get to spend a little less money the I thought!!!
Reply
Old Dec 10, 2008 | 05:29 PM
  #11  
Redeasysport's Avatar
Redeasysport
Le Mans Master
 
Joined: Dec 2004
Posts: 5,789
Likes: 8
From: Myrtle Beach SC
St. Jude Donor '05-'06
Default

Get the Bosch IIIs or what he suggests from John at FIC he is a forum Vendor. See his sticky at the top of the tech section. I would stay away from the Accel injectors nothing but bad about them.
Reply
Old Dec 10, 2008 | 06:08 PM
  #12  
psd_bullitt's Avatar
psd_bullitt
Thread Starter
Instructor
 
Joined: Jan 2008
Posts: 245
Likes: 0
From: McKinney Texas
Default

I called John and checked out his website.
His site has a great price. They are rebuilt but have a 3 year warrentee. He said the OEM injectors are not rated for the ethanol in gasoline these days so they start leaking and fail.
http://fuelinjectorconnection.com/sh...&productId=167

John confirmed that the LT4 needs 26lb injectors just like Corvettes of Dallas told me. According to the GrandSport Registry website the stock ones are 28lb for an LT4. It says LT1s have 24lb. I guess I'll ask Hutch at GSR what the deal is on that.

Thanks for the lead to this sticky thread for injectors:
http://forums.corvetteforum.com/c4-t...questions.html

.

Last edited by psd_bullitt; Dec 10, 2008 at 06:31 PM.
Reply
Old Dec 11, 2008 | 11:54 AM
  #13  
onedef92's Avatar
onedef92
Team Owner
20 Year Member
 
Joined: Oct 2000
Posts: 96,443
Likes: 9
From: Fort Knox, KY
Cruise-In IV Veteran
Cruise-In VI Veteran
Cruise-In VII Veteran
Cruise-In VIII Veteran
Default

I'd go ahead and replace the wires, wire holders, and looms, too.

If you've got more than 60,000 miles on your car, there's no better time on and LTX engine to replace the ignition wires than now.
Reply
Old Dec 11, 2008 | 12:11 PM
  #14  
RoperC4's Avatar
RoperC4
Racer
 
Joined: Mar 2007
Posts: 326
Likes: 0
From: McKinney Tx
Default

My water pump leaked all over my opti and it was an awesome time. Turned out all it did was solve problems I had been whining about on these forums for about a year with no conclusion.

I went with OEM unit I got off ebay for 100.00 (whole unit not just cap and rotor). And a new water pump obviously. I found a thread on here showing you how to use silicone and whatnot to seal the new unit better than it was from the factory. The reason I suggest and testify that is a good route to go is because I then sprang a seperate leak DIRECTLY over the opti again and it hosed it down pretty good and did not effect the opti whatsoever.

Good experience with stock unit replacement here.
Reply
Old Dec 11, 2008 | 12:11 PM
  #15  
RoperC4's Avatar
RoperC4
Racer
 
Joined: Mar 2007
Posts: 326
Likes: 0
From: McKinney Tx
Default

PS: I agree its a dandy time to go ahead and do your wires, plugs, cleaning, etc.
Reply

Get notified of new replies

To Optispark??? Too many Options!!!





All times are GMT -4. The time now is 06:20 PM.

story-0
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-1
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-2
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-3
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-4
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-5
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-6
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-7
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-8
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE
story-9
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE