A couple of months ago, I did a search on these forums and actually came up with a couple of threads talking about the Optispark. Here is a short list of links that I came up with and saved:
http://www.dynotech-eng.com/dynaspark.htm
http://www.corvetteclinicinc.com
http://www.corvettefever.com/howto/16758/

Someone else presently has a thread with distributor problems and they mentioned Dynotech and Corvette Clinic. However, the Corvette Fever link wasn't mentioned, so I decided to throw this thread up.

The reason I'm even doing this is because I have problems right now with, I assume, my distributor. :smash: :banghead: The car runs rough upon first cranking it, hesitating and backfiring until it warms up. Previous discussions have all pointed toward the Optispark. I have not done anything yet and have been living with it for a couple of years; it's probably a wonder I haven't stranded myself somewhere yet (knock on wood).

My question is, have any of you done any of the things listed in the links? Or have you done something not covered here? The other thread presently going talks about Dynotech having some problems with a new build of their distributor, so if I do anything soon, they're probably out. The Corvette Clinic solution would work great I'm sure, but it's a tad expensive (I'm not saying it's not worth the money, just it's more than I want to spend :nopity ). The Corvette Fever article, though, with the Chris dude from Corvette Clinic seems like a great read and is very thorough for anyone with a little experience working on cars. If I fix my distributor soon, I'm opting (ha ha) for making my own mods to a new distributor.

If anyone is having problems with their LT1 distributor, hopefully these links will help and at least get you on the right track. And again I pose some questions. Has anyone with Opti problems gone with any of these solutions? If so, how long has it lasted? Did you try some other solutions not listed in my few links?

Thanks!!!! :thumbs:


[Modified by semvhu, 4:57 PM 4/29/2003]

 

FWIW, if it was the opti, it would not go away after it warms up.

 

Well, it doesn't completely go away. There is still a bit of hesitation sometimes when starting off, but not always.

If it isn't the opti, what could it be? :confused: I've never replaced the distributor since I've owned it, and I've put almost 80k miles on the car since I bought it at 89k miles.

Thanks!

 

you need a complete tune up. wires, plugs... clean the throttle body. I would bet the IAC is dirty as hell, and the TPS is more than likely the cause of your off idle stumble.

Ultimately, I would replace the opti.

I am waiting for dynotech to get the first gen opti on the market.


[Modified by bogus, 9:06 PM 4/29/2003]

 

I'm one of the guys talking on that other thread. Yes, I went with Chris' venting. I would have done the whole thing myself, but I was worried about the vent tube attachment to the cap. So, for the $100 I had him do the venting on a new opti-spark from GM. To me it was good insurance that the job was done right and he did an outstanding job. I too am anxious about Dyno-tech's re design of the opti.

BTW, how's your coolant pump? Any signs of a leak? If so, it usually leaks right on the opti-spark.

:flag :flag :flag

 

bogus,

The TPS is only about 6 months old (10k miles), spark plug wires a year old (20k miles), and spark plugs 1.5 years old (30k miles). The spark plugs might be getting close enough to check again, but none of these things helped the problem at the time. :nonod: Good call, though, as sometimes it's the simple things that need checking. IAC? A quick 'net search resulted in "Idle Air Control Valve." I have no idea where that's at. :smash: The throttle body hasn't been cleaned since I've owned the car, and probably is extremely dirty. *sigh* I need to throw together an Excel spreadsheet (or something like that) to keep up with all my necessary maintenance.

Strick,

That's not a bad idea just to let Chris do it for $100, although I wouldn't mind the "learning experience." Sometimes, though, those "learning experiences" can cost you more in the long run. :lol: Coolant pump? I haven't actually checked it out, but since it possibly has the entire 168k miles on it, it will get replaced as well anyway since we'll be right there at it.

Another question for anyone watching: while I'm down there replacing the distributor and water pump, are there any good modifications that can be done on my LT1? Nothing extreme like new heads or cam, but something "simple" that can give me a few ponies.


Thanks guys, keep the suggestions coming! :thumbs:

 

Well, if you want a few more ponies, replace your water pump with an electric insert pump ie from Meziere. To make your ignition upgrade complete, upgrade your coil and coil driver from MSD. These are not big gains, but some.

:flag :flag :flag

 

Sorry for the uninformed questions, but are these links to what you're referring to? http://www.msdignition.com/1msdcoil.htm#anchor32098
http://www.meziere.com (water pumps, GM, chevy, small block)

Still not exactly a gearhead here. I rely on my dad for the experience side of things. :) :smash: Thanks again!


[Modified by semvhu, 1:06 PM 4/30/2003]

 

I checked your sites and the Meziere site didn't mention the LT-1 pump insert. I'm sure that if you call them, they will inform you of their product. If you have a Jeg's or Summit catalog, it is in there. There is also, a wiring harness and relay set listed in Jeg's from Painless Wiring, a good brand. This is what I'd buy to help with the installation.

The MSD site is correct. I bought the GM coil listed there. I bought it through Thunder Racing (listed on the left column) I think the part # is: pn 8226.

Still hope I'm helping

:chevy

:flag :flag :flag

 

The IAC valve is located on the bottom of the throttle body. It has a four pin connector that is reachable from the passenger side of the throttle body. You should remove the rubber accordian air hose to see it better and get a wrench on it to remove it. You likely have oil or other junk blocking the IAC circuit in the TB, at least by cleaning it all up you can eliminate that as a possible culprit. I'd recommend you purchase a set of the Helms Factory Service Manuals for a proper description of troubleshooting the idle circuit and other future reference issues. They can be had directly from them or off ebay too if you do auction stuff.

 

Thanks for the tip, Goody! I definitely need to try cleaning that first and see if it doesn't help things, as well as get the throttle body cleaned up. After those things, the last option AFAIK is the distributor. I'll chalk all this up as "experience." :cheers:

Thanks!!!!!! :thumbs: