Optispark gurus check in!
Thread Starter
Racer
Joined: Jan 2003
Posts: 360
Likes: 0
From: Sumter South Carolina
Optispark gurus check in!
Just before I left for Korea, my '94 Vette started to randomly stutter (like I completely lost ignition for a 1/2 sec). So, I figured it is my Opti since I have 47,000 miles on it and I do race the Vette. So, just before I put my Vette in storage, I looked at all of the plugs and they looked fine. From what I've read, about 50,000 miles is all I can expect out of an Opti. So, my dilema is I'm 6,000 miles away from the Vette, but when I get back I will have to fix this problem as I will have to drive it immediately. First, does this sound like a "typical" opti problem, and second where is the best/least expensive place to get one? Thanks for the help!
Last edited by Irishpilot03; Jul 25, 2006 at 12:11 AM.
Racer
Joined: Aug 2000
Posts: 488
Likes: 0
From: Fremont,CA
Originally Posted by Irishpilot03
Just before I left for Korea, my '94 Vette started to randomly stutter (like I completely lost ignition for a 1/2 sec). So, I figured it is my Opti since I have 47,000 miles on it and I do race the Vette. So, just before I put my Vette in storage, I looked at all of the plugs and they looked fine. From what I've read, about 50,000 miles is all I can expect out of an Opti. So, my dilema is I'm 6,000 miles away from the Vette, but when I get back I will have to fix this problem as I will have to drive it immediately. First, does this sound like a "typical" opti problem, and second where is the best/least expensive place to get one? Thanks for the help!
Safety Car
Joined: Feb 1999
Posts: 3,504
Likes: 4
From: Mexico Beach FL
You said you looked at all of the plugs and they looked fine, so this may not be your problem.
But, it is my opinion that the OEM AC double-platinum plugs that came from the factory in the LT1 and LT5 are JUNK.
It is well documented (Z28 Forum and ZR1 forums) that the platinum pucks frequently fall off of these plugs -- in my case, after 50K miles, ony two of the plugs had both of the platinum pucks still on them.
And, when the pucks fall off, the plug gap opens considerably -- if both pucks are missing, the gap opens to about .100".
The wider the plug gap, the more voltage it takes to fire that gap and that voltage is built up on the ENTIRE secondary of the ignition system -- including the cap and rotor of the Opti-Spark.
It is my belief that many Opti-Sparks failed prematurely because of internal arcing caused by the excessive voltage from the OEM AC double-platinum plugs.
I've been using Autolite double-platinum plugs in my AFR heads for over 35K miles and haven't lost a single puck since -- I wouldn't take an AC double-platinum plug if you paid me to.
Tom Piper
But, it is my opinion that the OEM AC double-platinum plugs that came from the factory in the LT1 and LT5 are JUNK.
It is well documented (Z28 Forum and ZR1 forums) that the platinum pucks frequently fall off of these plugs -- in my case, after 50K miles, ony two of the plugs had both of the platinum pucks still on them.
And, when the pucks fall off, the plug gap opens considerably -- if both pucks are missing, the gap opens to about .100".
The wider the plug gap, the more voltage it takes to fire that gap and that voltage is built up on the ENTIRE secondary of the ignition system -- including the cap and rotor of the Opti-Spark.
It is my belief that many Opti-Sparks failed prematurely because of internal arcing caused by the excessive voltage from the OEM AC double-platinum plugs.
I've been using Autolite double-platinum plugs in my AFR heads for over 35K miles and haven't lost a single puck since -- I wouldn't take an AC double-platinum plug if you paid me to.
Tom Piper
Last edited by Tom Piper; Jul 25, 2006 at 09:51 AM.
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
Most optis go longer than 50K, however mileage is not the only factor, it is also time and you do have a 94. My 94 went 95K and some go as long as 125K or longer depending on conditions and care.
Before I would personally point a finger at the opti, additional information would be helpful. Running conditions hot and cold, acceleration in high gear (how it takes throttle), the idle, random or constant problem, does tack jump around, and good description of symptoms.
Have you checked your codes. May not provide anything but a proper step to do in the troubleshooting process. I can’t say you have a typical problem because I don’t know enough yet. The best price I have found was on Ebay from “the_parts_lady”, but I don’t think you are to that point yet. Many other causes to consider for your problem. Optis cause a variety of symptoms and sometimes it takes a while to pin it down. Being in Korea I understand your urgency to get into in when you get back. But you want to go in the right direction also.
Been to Korea many times myself and Osan AFB with the shopping and all. When are due to come back? The more communication you have now the better prepared you might be later.
Before I would personally point a finger at the opti, additional information would be helpful. Running conditions hot and cold, acceleration in high gear (how it takes throttle), the idle, random or constant problem, does tack jump around, and good description of symptoms.
Have you checked your codes. May not provide anything but a proper step to do in the troubleshooting process. I can’t say you have a typical problem because I don’t know enough yet. The best price I have found was on Ebay from “the_parts_lady”, but I don’t think you are to that point yet. Many other causes to consider for your problem. Optis cause a variety of symptoms and sometimes it takes a while to pin it down. Being in Korea I understand your urgency to get into in when you get back. But you want to go in the right direction also.
Been to Korea many times myself and Osan AFB with the shopping and all. When are due to come back? The more communication you have now the better prepared you might be later.
Le Mans Master
Joined: May 2005
Posts: 7,337
Likes: 2,266
From: Central Maryland
This may or may not be an Opti problem. If you're not getting a code 16 or 36, the optical side of the unit should be fine, but the high-voltage (distributor) side could be failing. I'd try to troubleshoot the problem before throwing an Opti at it.
If you do need an Opti, I'd strongly encourage you to NOT install another OEM Opti. The first-gen OEM units are inherently deficient. Instead, consider the DynaSpark or the new unit from MSD. The Dyna has a good record in the field. The MSD is new to the market, and looks good but long-term reliability data is not available yet.
Be well,
SJW
If you do need an Opti, I'd strongly encourage you to NOT install another OEM Opti. The first-gen OEM units are inherently deficient. Instead, consider the DynaSpark or the new unit from MSD. The Dyna has a good record in the field. The MSD is new to the market, and looks good but long-term reliability data is not available yet.
Be well,
SJW
Melting Slicks
Joined: Nov 2004
Posts: 2,799
Likes: 2
From: Cape Coral FL
Agreeing with most here...look at your plugs and wires very closely before condemning the Opti (if no codes for it)... Most Opti failures are traced to coolant intrusion contaminating the optical pickup (look at the water pump for leaks), and not just random failures.
If you have a bad wire or plug, the higher voltage needed to cross the gap can damage the Opti's cap and rotor (create hot spots, etc.). You can replace the cap and rotor without having to replace the entire Opti unit itself.
Good luck and keep us posted!
If you have a bad wire or plug, the higher voltage needed to cross the gap can damage the Opti's cap and rotor (create hot spots, etc.). You can replace the cap and rotor without having to replace the entire Opti unit itself.
Good luck and keep us posted!
Thread Starter
Racer
Joined: Jan 2003
Posts: 360
Likes: 0
From: Sumter South Carolina
I installed headers a few months prior to the problems. I was having issues with one of the driver's side wires getting hot from the header. It didn't burn through, but that may be the source. The car idles fine, no codes, and pulls smoothly through the rpm range. However, randomly, especially around town the car would suddenly lurch (feeling like I lost spark for 1/2 sec or so), and then go back to normal. Other times cruising in 6th gear with low rpms, the car will do the same thing, once or twice in a row and then go back to normal.
pcolt94, yeah the shopping is pretty good in Songtan and in the Bx. I PCS back to the states in January, but I was thinking about working on the car in November when I go back for a week of leave. When was the last time you were here?
pcolt94, yeah the shopping is pretty good in Songtan and in the Bx. I PCS back to the states in January, but I was thinking about working on the car in November when I go back for a week of leave. When was the last time you were here?
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Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
check the coil wire, too. they are prone to chaffing, which leads to a ground out condition.
For the most part, short of lots of moisture related problems, and opti should last a minimum of 65k miles. This is under the assumption it's driven regularly.
A gen II opti should last upwards of 125k miles.
For the most part, short of lots of moisture related problems, and opti should last a minimum of 65k miles. This is under the assumption it's driven regularly.
A gen II opti should last upwards of 125k miles.
Thread Starter
Racer
Joined: Jan 2003
Posts: 360
Likes: 0
From: Sumter South Carolina
Moisture is not a problem. I never spray the engine bay, and the car is kept in Arizona and it's a garage queen. I don't drive it that regularly since it is my "weekend" car, and it sees less than 3,000 miles a year. From what you guys are saying, when I get back I'll change out the plugs and wires first. If that doesn't work, then I'll check the coil; and if that still doesn't fix it, I'll get a dynaspark or MSD opti. Thanks for all of the good info so far!
Melting Slicks
Joined: Nov 2004
Posts: 2,799
Likes: 2
From: Cape Coral FL
Originally Posted by Irishpilot03
I installed headers a few months prior to the problems. I was having issues with one of the driver's side wires getting hot from the header. It didn't burn through, but that may be the source. The car idles fine, no codes, and pulls smoothly through the rpm range. However, randomly, especially around town the car would suddenly lurch (feeling like I lost spark for 1/2 sec or so), and then go back to normal. Other times cruising in 6th gear with low rpms, the car will do the same thing, once or twice in a row and then go back to normal.
Safety Car
Joined: Jul 2001
Posts: 4,871
Likes: 15
From: Detroit's West Side MI
Originally Posted by Irishpilot03
Moisture is not a problem. I never spray the engine bay, and the car is kept in Arizona and it's a garage queen. I don't drive it that regularly since it is my "weekend" car, and it sees less than 3,000 miles a year. From what you guys are saying, when I get back I'll change out the plugs and wires first. If that doesn't work, then I'll check the coil; and if that still doesn't fix it, I'll get a dynaspark or MSD opti. Thanks for all of the good info so far!
You're in a bit of a time crunch if you're only home for a week, so you may not have the luxury of a deep dive. However, I'd like to add to the list others have suggested before you replace anything (except plugs, those are cheap
). I'm one of the many who have thrown parts at a car to fix a problem only to have an empty wallet and a car that won't run.Easy things to check which might account for a stutter:
- Plugs
- Wires - check the resistance. Don't spend $100 on new wires if they're fine
- Coil - there's a nice step-by-step on the forum, I think Bogus wrote it, for how to check your coil
- Ignition module
- Injectors
There aren't many sure-fire ways to prove it's an opti. But the two magic codes - 16 and 34 (hi and lo resolution opti signals) are bad news.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Originally Posted by ScaryFast
I'm happy to see that the forum advice is no longer "go replace your opti, that's the problem." I mistakenly did mine twice because the symptoms seemed to say "opti" and I was too lazy to troubleshoot other possible causes.
You're in a bit of a time crunch if you're only home for a week, so you may not have the luxury of a deep dive. However, I'd like to add to the list others have suggested before you replace anything (except plugs, those are cheap ). I'm one of the many who have thrown parts at a car to fix a problem only to have an empty wallet and a car that won't run.
Easy things to check which might account for a stutter:
There aren't many sure-fire ways to prove it's an opti. But the two magic codes - 16 and 34 (hi and lo resolution opti signals) are bad news.
You're in a bit of a time crunch if you're only home for a week, so you may not have the luxury of a deep dive. However, I'd like to add to the list others have suggested before you replace anything (except plugs, those are cheap
). I'm one of the many who have thrown parts at a car to fix a problem only to have an empty wallet and a car that won't run.Easy things to check which might account for a stutter:
- Plugs
- Wires - check the resistance. Don't spend $100 on new wires if they're fine
- Coil - there's a nice step-by-step on the forum, I think Bogus wrote it, for how to check your coil
- Ignition module
- Injectors
There aren't many sure-fire ways to prove it's an opti. But the two magic codes - 16 and 34 (hi and lo resolution opti signals) are bad news.
Safety Car
Joined: Jul 2001
Posts: 4,871
Likes: 15
From: Detroit's West Side MI
Originally Posted by bogus
make that code 36 and you got it right!
Of course, mine's a '93, what's code 34 for you 1994+ MAF guys?
