replacing optispark
Heel & Toe
Joined: Dec 2003
Posts: 22
Likes: 0
From: Germantown MD
The timing cover isn't involved, but when you get into it you'll think that it's about the only part on the front of the engine you're not having to mess with. While you have the cover exposed, it is a good time to clean off the front of the engine, including the timing chain cover.
I've done this job twice. The hardest part of the job the first time was removing the outer part of the harmonic balancer. It detaches from the hub by removing three bolts. I had to drive the hub off by using a long brass rod and a two pound hammer from the back side while a friend rotated the crankshaft occasionally. Be careful to hit only the the "arms" that extend from the center. If you hit the outer ring, you will probably damage the balancer. If you look from under the oil pan, but over the crossmember you can see the back of the balancer.
The second hardest part was wiping the coolant off my face when I let the knock sensors fall into the drip pan when they came loose!
Good luck. Write back or e-mail me if you need more help.
I've done this job twice. The hardest part of the job the first time was removing the outer part of the harmonic balancer. It detaches from the hub by removing three bolts. I had to drive the hub off by using a long brass rod and a two pound hammer from the back side while a friend rotated the crankshaft occasionally. Be careful to hit only the the "arms" that extend from the center. If you hit the outer ring, you will probably damage the balancer. If you look from under the oil pan, but over the crossmember you can see the back of the balancer.
The second hardest part was wiping the coolant off my face when I let the knock sensors fall into the drip pan when they came loose!
Good luck. Write back or e-mail me if you need more help.
Heel & Toe
Joined: Dec 2003
Posts: 22
Likes: 0
From: Germantown MD
One other thing, the water pump is held on with 6 bolts - only four of which are easy to find. Also, be sure to note the direction of the coupling that connects the water pump to the shaft on the engine. Th eends of the shaft are not necessarily the same. People who forget to reinstall this shaft have found that their Vettes overheat. It's no wonder since their water pumps aren't connected!
Thread Starter
Safety Car
Joined: Apr 2004
Posts: 3,997
Likes: 1
From: WAY DEEP INSIDE AMERICO,YES YOU LIVE HERE TO!! TX
So this is easy to do 
. Also are there any dots or lines to line
up when reinstalling the optispark? does #1 cylinder have to be TDC,
or it does not matter how you install it.
. Also are there any dots or lines to lineup when reinstalling the optispark? does #1 cylinder have to be TDC,
or it does not matter how you install it.
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
Originally Posted by MEGLADON
So this is easy to do . Also are there any dots or lines to line
up when reinstalling the optispark? does #1 cylinder have to be TDC,
or it does not matter how you install it.
. Also are there any dots or lines to lineup when reinstalling the optispark? does #1 cylinder have to be TDC,
or it does not matter how you install it.
When you have fitted the Opti correctly, it will be flush with the matting surface, and you will know it when it happens. Flush is when the pin is inside the indexed groove and there is no 'play' with respect to the 3 mounting points on the Opti.
Last edited by MikeC4; Apr 6, 2005 at 05:20 PM.
Melting Slicks
Joined: May 2001
Posts: 2,143
Likes: 7
From: San Diego CA
Aligning the opti, is a little different on 92-94 cars. The shaft has a keyed spline. I insert it into the cam then align the opti. I usually takes me 3-5 shots at getting it aligned. But when it slides on it slides on easy and without any force.
As to symptoms, both times I had to replace my, it first started with a random high rpm miss, then progressively lower rpms and more often misses, finally a jumpy idle. It did almost strand me, but I let it cool for a few minutes and tried it again and it started.
There are 2 codes (low resolution and high resolution sensors - CRS - I don't remember the numbers) that it will sometimes fire. But that's only if the optics are failing. If the high voltage side is failing, no codes.
The first opti I replaced shocked me with its condition when I opened it. I was surprised the engine ran at all.
As to symptoms, both times I had to replace my, it first started with a random high rpm miss, then progressively lower rpms and more often misses, finally a jumpy idle. It did almost strand me, but I let it cool for a few minutes and tried it again and it started.
There are 2 codes (low resolution and high resolution sensors - CRS - I don't remember the numbers) that it will sometimes fire. But that's only if the optics are failing. If the high voltage side is failing, no codes.
The first opti I replaced shocked me with its condition when I opened it. I was surprised the engine ran at all.
Advanced
Joined: Nov 2004
Posts: 66
Likes: 0
From: Vacaville CA
Get Rid Of It Goto Opti Direct
dump the opti spark crap and goto opti direct site order bare bones and get coils from ebay and your set, runs stonger smoother and looks cool 8 coils are better than one and no moving parts, i love it and my cars runs way way way better, u just leave the crap their and install this, mine with everything cost about $400 and took about 1 hour
http://photobucket.com/albums/y126/e...orvette003.jpg
http://i4.photobucket.com/albums/y12...orvette003.jpg
http://photobucket.com/albums/y126/e...orvette003.jpg
http://i4.photobucket.com/albums/y12...orvette003.jpg
Last edited by ericdiver; Apr 6, 2005 at 11:26 PM.
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Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
Originally Posted by ericdiver
dump the opti spark crap and goto opti direct site order bare bones and get coils from ebay and your set, runs stonger smoother and looks cool 8 coils are better than one and no moving parts, i love it and my cars runs way way way better, u just leave the crap their and install this, mine with everything cost about $400 and took about 1 hour
http://photobucket.com/albums/y126/e...orvette003.jpg
http://i4.photobucket.com/albums/y12...orvette003.jpg
http://photobucket.com/albums/y126/e...orvette003.jpg
http://i4.photobucket.com/albums/y12...orvette003.jpg
Is Your Opti-Spark Failing?
LT1 owners have dealt with the Opti-Spark distributor for 11 years now, but there is still much confusion regarding the causes and symptoms of a failing unit. Tapping into the PCM with a scan tool is a good way to start, but sometimes no codes will be set. Before diving into the Opti-Spark, be sure to verify that your grounds are good and the coil and wires are not the source of the problem, as they are much easier to change.
Symptoms:
* Car suddenly dies and won't restart
* Starts but immediately dies
* Extended cranking to start
* Rough idle
* Sputtering
* Backfiring
* Trouble reaching higher rpm
* Black smoke from exhaust
* Poor performance with car warmed up
* Weak plug wire spark
* Codes 16, 36, and 42 may be set
