OptiSpark distributor

[cmaje72]

Stupid optispark.....

[EagleMark]

Optispark very intelligent! Human design flaws stupid... what happened?

[cmaje72]

Well, it has not happened yet but it is cold, wet, and snowy here this morning. All of the things the opti hates. Started missing on more than one cylinder on the drive into work. Once the engine got good and warm it cleared up but in my experience this is the beginning of the end for the opti.

Its the non-vented design which I modified to vented when I had to replace the timing cover gaskets around a year ago. I didn't open it up at the time since I didn't have the proper bit and had to get the truck back together quick. Whoever owned it before me put a vented cap on it and didn't seal up the vent. I'm sure its nasty and rusty in there.

Now the problem is that to get a decent opti its around $250 if you can even still find an oem one. I'm seeing 5.3's for sale in the $350 range...

[EagleMark]

All that can be cleaned up. The trigger wheel and original sensor are most important, then new cap and rotor which has the shield with Oring. Of course getting it sealed properly so the vent can work is key. Little sealer around bearing is sometimes needed.

There's lots for sale new and cheap, Chandler has one for $139. with lifetime warranty, get one with good bearing, cap and rotor and use your wheel and sensor, sometimes the harness between it and ICM is also pretty work from location.

Many a stock vented Opti has made over 250k miles. Maintenance is replace cap, rotor, shield with o ring seal every 100k miles. Mine has 125k and I ran a water hose on it when warmed up with no issues, no issues rest of week either, that was months before car was wrecked. I am going to get a new aftermarket Opti with cap rotor an harness and use my original sensor and wheel. While I have the motor out for cleaning, resealing maintenance etc... before dropping it in a new car.

The Opti Vent system is just vacuum hose with a filter and one way valve. I am going to find them at parts store for affordable vent system replacement. $60 for vacuum line a filter and one way valve just piss's me off! When done I can copy it and do a vented system on TBI small cap EFI distributors which will extend their life. If it had one they would not get all that green corrosion all over pickup coil and wires.

[EagleMark]

You know you can't just change the cap? Maybe the vented cap will fit I don't know but if it is an earlier non vented Opti it has vent/drain holes in bottom...

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

[cmaje72]

Stop that...I'm trying to justify a LS engine swap and your not helping.

I think that the vented opti's are a little more robust than the early ones. I have no idea what the history on this one is. The cap is definitely not stock. Have you used any of the chandler opti's? I have read some bad reports on them.

[EagleMark]

You'll read all sorts of bad things about aftermarket Optisparks because there are so many cheap chinese knockoffs, look at pictures of the sensor and see how cheap ones are compared to good ones. Then there are so many guys convinced there Opti is bad and a new aftermarket doesn't fix the issue which had nothing to do with distributor in first place.

New GM opti is $350. with cap and rotor. New vent and harness another $100. New GM cap and rotor is $175. bout the same as MSD which I would rather have GM over MSD. Buy a Chandler or other at $139 to $100, all you need is a new bearing which is not available I have looked hard! And a new cap and rotor with O ring sheild and use the origanal Mitsubishi optical sensor.

But you need one to mount to your engine, 92 - 93 are differant then 94 up. Differant timing cover, cam, seal shaft etc...

I have not used the Chandler yet but am ordering one, there are others as well have not decided, I'm more interested in bearing, cap and rotor quality. But I have three origanal Mitsubishi optical sensors and wheels, so all I need is a new distributor with bearing, cap and rotor.

If the O ring seal is good there is no issue, but some guys are installing cap with silicone as well. Bearing is pressed in and my checking shows it to leak vacuum, so seal it, some aftermarket units have addressed this with better bearing and tolerences that don't leak like origanal GM opti...

[cmaje72]

You know you can't just change the cap? Maybe the vented cap will fit I don't know but if it is an earlier non vented Opti it has vent/drain holes in bottom...

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

Yep, I actually followed that very same article when I modded the non vented one.

[EagleMark]

Here's a link to an Opti, he also has the earlier ones. Notice he has Mitsubishi optical encoders and pictures of cheap knock offs! Only one year warrenty unlike Top Shelf brand from Chandler that has liftime warrenty. But chandler also has cheaper ones with less warrenty.

http://www.ebay.com/itm/170582148913...84.m1438.l2649

[cmaje72]

I think thats the supplier that was busted a few years ago selling counterfeit GM units. General consensus was to stay away from them.

[EagleMark]

Hmm? He's got a good rating on eBay! If they were good enough to be GM fakes maybe the best of bunch!

Chandler still has lifetime warrenty. But also has one cheaper with one year warrenty. Also another one has bigger bearing and rated to 10K RPM.

Point was GM prices on these is ridiculas and only questionable part is the optical sensor, so if you have a stock Mitsubishi sender all you need is a new distributor bearing cap and rotor. These aftermarkets are priced from $59 to $164. Seen at least four differant names but who knows if they are all the same or if one stands out!

If I had the cash I would buy a few and compare. Then do a writeup and return them except the best. Still holding off buying one because the other LT1 car I bought that needs a motor, has rod knock, looks to have a new opti and vent harness. Mine also runs fine with no issues so I have a good optical sender and wheel, have to check bearing, but want a cap and rotor while the motor is out and replacing seals behind opti then waterpump.

[EagleMark]

Rich Porter, made in USA, limited lifetime warrenty. Comes with car rotor and harness complete bolt in $101...

http://www.amazon.com/dp/B001DAHM2A/...SIN=B001DAHM2A