Has anyone on here had to replace their optic sensor and done the work them selves? If so is it something someone could do with limited experience?

 

I suspect you are talking about the Opti-Spark Distributor. I think with the correct tools and information, someone with patience and limited wrenching experience can do this job. You need the Factory SErvice Manual for your year car to get you rolling.

 

thanks biggrizzly,yes the optic distributor..(i have ordered a manual) i have just never attempted a repair of this magnatude..

 

The opti is a BIG job. It can certainly be done by the average back yard mechanic. However, it takes some time to do and is very cumbersome! I believe if you search the tips section on this forum there is an excellent write up on doing the job. I followed it when i did mine and it came out great! You definately want to vent it, which is an upgrade that came in 94. Even that wasn't to bad to do. Here's the link to the venting article....excellent guide....

http://www.corvettefever.com/howto/16758/

You will certainly learn a lot about your car by doing this job. If you have not already gotten to them you will most likely want to change the water pump, coil, plugs, and wires while your at it! Probably hit the tb bypass, a new air filter, and serp belt too!

Good luck!

 

I'd STRONGLY encourage you to NOT install another OEM Opti in your '92. The '92 used the deficient first-generation Opti, and a replacement unit will be as deficient as the one you're removing.

Consider the MSD as an aftermarket solution that should serve you much better than the OEM replacement. If DynaSpark is still in business (which seems to be in doubt these days), consider their product as well.

If you have a good set of general mechanic's tools, and decent mechanical skills, you can tackle the Opti swap yourself. No special tools are required. Here are a few tech tips I wrote up some time ago about doing an Opti swap:

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Get a Factory Service Manual, and follow the procedure it lays out.

A few tips (I'm going from memory here, so I'll probably forget a few things):

Drain the cooling system.

Disconnect the MAF sensor and IAT sensor and remove the air intake duct with the MAF and IAT as an assembly.

Disconnect the ECT sensor and remove it from the water pump.

Remove the serpentine belt and tensioner.

You may find that you’ll need to unbolt the coil/ICM bracket from the front of the right cylinder head. I can’t recall for sure whether or not I did.

Unbolt (but don't remove) the power steering pump. This will help you to sneak the new plug wires in/out behind the pump, but may also be somewhat helpful when working on the water pump/Opti.

If you want more room to work, you can remove the radiator, but it isn't strictly necessary, and it involves considerably more work to remove it (I left mine in place).

The FSM will tell you that you need a special Kent-Moore puller to remove the crank pulley/damper. You don't. Here's how to get it off:

1. Raise the front of the vehicle enough that you can get under the car (it's also helpful to have it at a more comfortable height while you're working from above).

2. Remove the three bolts that secure the pulley/damper to the hub.

3. Mark the damper and hub so that you can easily see how to realign them to each other later.

4. Slide under the car with a long pry bar or hardwood dowel (I use a jumbo Snap-On screwdriver that's around two feet long) and a mallet.

5. Place the tip of the pry bar against the rear face of the damper, as close to the hub as possible (Ideally rest the tip alongside of the hub).

6 Give the pry bar a few whacks with the mallet, and with any luck the damper will pop off without too much of a fight.

You may find it helpful to apply a few whacks, then rotate the crankshaft in 120* increments, whacking it a few times at each interval (I haven't needed to do this).

It's also helpful to, if possible, shoot a bit of penetrating oil where the damper meets the hub, a day or more in advance of doing the job.

After you get the damper off, clean the damper/hub mating surfaces to remove all corrosion, etc, and apply a very thin coating of anti-sieze compound to these surfaces before you reassmble the damper to the hub. This should make it a lot easier to get the damper off next time.

Once the damper is removed, rotate the crankshaft so that one wing of the damper hub is at the six-o'clock position. This will position the other two wings at around the ten- and two-o'clock positions. In this orientation, the Opti will clear the hub as it is being removed/installed.

The Opti basically unbolts and pulls off as you'd expect, once you have the water pump and damper out of the way.

Once the Opti is out of the way, inspect the shaft seals for the Opti, water pump, and crankshaft. If they show any signs of leakage, replace them now.

When you install the new Opti, be sure to align it correctly with the cam gear, and don't force it into place against the timing cover (do NOT use the bolts to draw it into place). At most, give it a gentle bump with the heel of your hand to encourage it to pop into place.

Reassemble everything else.

Follow the cooling system refill procedure in the FSM carefully, and you'll have no problems with this. In particular, be sure to bleed the air out of the system as it's being refilled.

Hope this helps. Best of luck with it.

Live well,

SJW

 

The opti can be changed without any special tools. I did it this past spring. Take your time and it's not too bad. I went back with the Genuine GM optispark, but if/when I have to do it again it will be with the MSD unit, it more expensive but I think it is a bit more secure/better built. SJW has given you a pretty good list and suggestions, but do purchase the FSM.

 

Gentlemen, thank you very much for your imput, you are truly a wealth of knowledge..! I am going to attempt this myself and let you know the outcome..again many thanks!

 

If you replace the 92 Opti with a GM, you'll still need to get the vent line kit or make one to keep the inside of the Opti dry ( like the 95-96).
I highly recommend the MSD, higher quality and better seal than the GM and comes with the vent line.
If you get the MSD, install the lower vent hose on the Opti before you put it on the engine, it's easier this way.

The connector on the MSD will not plug into a 92 Vette harness. This is no big deal, you just have to solder and heat shrink the 4 wires. Here's the wiring connections that aren't in the MSD instructions:

Here's the wire connections:
92 LT1 MSD

black/red(stripe) to brown/yellow - low resolution
purple/white to brown/orange - hi res
yellow to red - 12 volt
black/pink to red/green - ground

The 5th wire in the LT1 harness is a ground/shielding wire. It's not needed on the MSD Opti. It doesn't connect to anything on the GM Opti either, just wraped around the other 4 wires for shielding.

 

I agree with all of the above. Also, be very sure to get the the firing order correct. The order is etched on the opti. Cause if you don't and you get it all back together, the drivers side wires are now buried and a major pain to resort. (ask me how I know). Todays average person would be very intimadated just looking at this repair.
Good luck!

 

EXCELLENT point.