Does This Sound Like an OPTI Issue??
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 9,700
Likes: 3,469
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
Does This Sound Like an OPTI Issue??
My dad and I tried to autocross his '92 Z07 6-speed yesterday. He went first and was able to make 2 out of the 4 runs and then the engine started missing and popping. It also got very hot, so we started looking for issues. The secondary fan does not come on so that would explain why it gets hot, but it only pops and misses when it is hot. By the time I tried to drive it it would miss and jerk and pop with any kind of load (just getting started from a stop it wanted to stall). After letting it cool all day it drove home fine with full power, but on the highway following other cars it got hot again and started missing.
I have heard upgrading to a vented opti is best? What would be a good replacement for my dad's '92? Is there anything else that should be done while we are in there? I assume the water pump and thermostat gasket since those are prone to leaking and killing optis. The car has almost 150K miles on it and we have not done anything to it since my dad bought it last year.
I have heard upgrading to a vented opti is best? What would be a good replacement for my dad's '92? Is there anything else that should be done while we are in there? I assume the water pump and thermostat gasket since those are prone to leaking and killing optis. The car has almost 150K miles on it and we have not done anything to it since my dad bought it last year.
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 9,700
Likes: 3,469
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
Coolant was 230-240 or so. It was full of coolant. The secondary fan stopped working thats why it got so hot.
I thought MSD made an opti that was vented for the early non vented cars? This is just his daily driver that we drove for fun yesterday because the race car isnt done yet. We dont want to have to change a cam if we dont have to.
Edit: This MSD unit at Summit is vented, and is made for the early style opti.
http://www.summitracing.com/parts/MSD-8381/
By the time I buy all the OEM vented components I would have spent as much as a nice MSD opti, unless the MSD unit isnt that great? Should I just get a new GM one? I dont want to have to replace this again.
Edit: This MSD unit at Summit is vented, and is made for the early style opti.
http://www.summitracing.com/parts/MSD-8381/
By the time I buy all the OEM vented components I would have spent as much as a nice MSD opti, unless the MSD unit isnt that great? Should I just get a new GM one? I dont want to have to replace this again.
Last edited by Kubs; May 31, 2011 at 11:47 AM.
Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
The MSD is a good unit.
My personal experience has been that checking the O-Ring/Seal on the cap (make sure it's seated correctly) and inspecting then loctiting the rotor screw will solve 99% of problems people who take them out of the box and install them without checking anything have with it.
Will
My personal experience has been that checking the O-Ring/Seal on the cap (make sure it's seated correctly) and inspecting then loctiting the rotor screw will solve 99% of problems people who take them out of the box and install them without checking anything have with it.
Will
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 9,700
Likes: 3,469
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
Do you have a source or link for this kit?
Thanks for the tip Will.
Im an L98 guy so I only know what others have talked about on here about optis.
The MSD is a good unit.
My personal experience has been that checking the O-Ring/Seal on the cap (make sure it's seated correctly) and inspecting then loctiting the rotor screw will solve 99% of problems people who take them out of the box and install them without checking anything have with it.
Will
My personal experience has been that checking the O-Ring/Seal on the cap (make sure it's seated correctly) and inspecting then loctiting the rotor screw will solve 99% of problems people who take them out of the box and install them without checking anything have with it.
Will
Im an L98 guy so I only know what others have talked about on here about optis.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Former Vendor
Joined: Nov 2006
Posts: 2,482
Likes: 3
From: Carmichael ca
Your car should not run 230-240 on the highway even if both fans don't work. That's OK in at low, no speeds, if the fan comes on and brings it down. On the highway you'll have enough airflow without the fans.
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 9,700
Likes: 3,469
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
Thats was racing temp. I dont know what it was on the highway (dad was driving) but it was hot enough to make the car start missing.
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 9,700
Likes: 3,469
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
Drifting
Joined: Aug 2009
Posts: 1,972
Likes: 243
I'd consider the coil or ICM getting heat soaked and causing those problems before the opti. It happened to me and the ICM was the culprit. Would only do it once the engine got good and hot.
Also, how much gas did you have? These cars slosh the fuel away from the pickup when the tank gets low. If I try to accelerate hard with only a few bars of fuel on the gauge the engine will studder. It will do this well before the reserve light comes on.
Also, how much gas did you have? These cars slosh the fuel away from the pickup when the tank gets low. If I try to accelerate hard with only a few bars of fuel on the gauge the engine will studder. It will do this well before the reserve light comes on.
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 9,700
Likes: 3,469
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
My '90 does the same thing. We had a full tank. It definitely felt like a spark issue not a fuel issue.
Drifting
Joined: Aug 2009
Posts: 1,972
Likes: 243
The icm is the module located next to the ignition coil. Look near the power steering pump reservoir. Aftermarket (autozone etc) icms are around $100 I believe. I had really bad luck with junk aftermarket icms, my suggestions would be to have it tested and if determined to be defective find a used or oem replacement.
After much frustration with bad coils and icms I switched over to ls1 coil packs using the ltcc unit (still uses opti signal but not the high voltage side). I've had zero ignition problems since then and still use m factory original opti.
After much frustration with bad coils and icms I switched over to ls1 coil packs using the ltcc unit (still uses opti signal but not the high voltage side). I've had zero ignition problems since then and still use m factory original opti.
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 9,700
Likes: 3,469
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
The icm is the module located next to the ignition coil. Look near the power steering pump reservoir. Aftermarket (autozone etc) icms are around $100 I believe. I had really bad luck with junk aftermarket icms, my suggestions would be to have it tested and if determined to be defective find a used or oem replacement.
After much frustration with bad coils and icms I switched over to ls1 coil packs using the ltcc unit (still uses opti signal but not the high voltage side). I've had zero ignition problems since then and still use m factory original opti.
After much frustration with bad coils and icms I switched over to ls1 coil packs using the ltcc unit (still uses opti signal but not the high voltage side). I've had zero ignition problems since then and still use m factory original opti.
I looked into the coil pack deal and it gets pretty pricey. My dad just wants to drive the car. Mine is the one being built for racing.
Safety Car
Joined: Jul 2001
Posts: 4,871
Likes: 15
From: Detroit's West Side MI
Kubiak PM me your email, I have lots of documents I can send regarding the vented kit, '95 upgrade, and a nice troubleshooting step by step guide for checking if your opti, ICM, and coil are good or bad.
If you do end up needing an opti I can do it in about an hour now...although I'm a bit rusty as mine doesn't eat them up anymore.
Don't buy the MSD. If you want mine you can have it cheap, it's been sitting on the bench for two years...oh, did I mention it failed just as easily as the stock ones?
If you do end up needing an opti I can do it in about an hour now...although I'm a bit rusty as mine doesn't eat them up anymore.
Don't buy the MSD. If you want mine you can have it cheap, it's been sitting on the bench for two years...oh, did I mention it failed just as easily as the stock ones?
Cruising
Joined: May 2011
Posts: 13
Likes: 0
From: PA
Kubiak PM me your email, I have lots of documents I can send regarding the vented kit, '95 upgrade, and a nice troubleshooting step by step guide for checking if your opti, ICM, and coil are good or bad.
If you do end up needing an opti I can do it in about an hour now...although I'm a bit rusty as mine doesn't eat them up anymore.
Don't buy the MSD. If you want mine you can have it cheap, it's been sitting on the bench for two years...oh, did I mention it failed just as easily as the stock ones?
If you do end up needing an opti I can do it in about an hour now...although I'm a bit rusty as mine doesn't eat them up anymore.
Don't buy the MSD. If you want mine you can have it cheap, it's been sitting on the bench for two years...oh, did I mention it failed just as easily as the stock ones?
it sucks coming out of turn 1 at pocono and the engine dies....
Drifting
Joined: Aug 2007
Posts: 1,846
Likes: 129
From: Orlando Florida
My ICM gave me the same issues you are having. See if you can loan one and try it. Also, my fans used to run all the time even when not needed, I cant explain it but since I put a brand new ICM on it has quit doing that.