I have hear a lot of bad things about this opti thing. exactly what does it do and what does it look like so i make sure i don't do anything to it. I'm no mechanic so im not very knowledgeable about these things. pics would be nice. and no i am not planning on washing my engine bay. just want to know what it looks like so i can curse at it.

 

The Optispark is an ignition distributor. It has a cap & rotor to distribute spark from the ignition coil to the correct spark plug, and a perforated optical triggerwheel that works with two photodetectors. The optical section feeds camshaft position, velocity and acceleration data to the ECM (engine's computer), which then decides exactly when to fire the ignition coil.

It's nearly impossible to see the Opti with everything fully assembled. It's bolted to the front of the engine, behind and below the water pump, and is driven directly via a mechanical coupling to the front of the camshaft.

Does this help?

Be well,

SJW

 

For more details, aim your browser here:

http://www.gmhightechperformance.com...htp_optispark/

Be well,

SJW

 

OPTI = Probably worst Gm idea in the last 50 years

 

Basically you could take a sledge hammer and beat the crap out of your engine and still not harm the opti at all. It's so far down under there.

However, a teaspoon of coolant will destroy it.

 

Good info so far and here is some additonal operational details

The way the whole system works is the reference pulses from the opti tell the ECM/PCM what the crankshaft position is and what cylinder next to fire. Then the ECM/ PCM takes all the sensor inputs from the engine (MAP, TPS, temp etc) and determines spark timing. It then sends a pulse to the ICM. This will advance or retard as needed. Since the pulse is real small at 5 volts it can’t drive the coil. So it’s function in life of the ICM is to amplify this pulse to a level big enough to drive the coil. There is about 40 volts applied at the same frequency to the primary of the coil and hence the secondary produces the 25K volts which goes to the cap of the opti. The rest you know, the rotor is at the correct position and fires to that plug like any other system.

It’s really a neat system and the precision is with in 1 degree error in timing. The reference pulses are 720 per camshaft revolution or 360 per crankshaft. I use to wonder why thy put the darn thing on the front of the engine. But now in my opinion it was for accuracy. There is to much slop in a regular shaft and gears and direct off the cam takes the error out. Charge on

 

About 3 months ago I thought I lost my opti when the upper radiator hose burst all over the opti. In fact I got stranded and had to get towed in. I got the code 36 and most here said that was the opti death code and to go get a new one. After sitting at the stearlership for about 3 weeks he said my coil wire was bad and not the opti itself. So since replacing the coil wire I haven't had the slightest problem yet. Knock on wood.

 

My coil wire went bad to. Right at the opti was arking to the waterpump. It was never wet and caused a no start condition at times or sometimes rough running. Had it running one day and looked down and saw a few arks, right place, right time. Changed the wire ($22) and good to go. You got lucky, the water killed the spark before the opti got wet while it was running. Sitting for a while could have saved the opti cap from arking and carbon tracking. If you ran it right away you might have kiled it but who knows. Charge on