96LT4_CE

I know this has been discussed a million times but I need to know what the best optispark is to go with currently. Pretty sure mine us bad. Skipping at high rpm. Multiple misfire. Poor mpg. I already checked the fuel pressure and it's all good. I planned on replacing it this summer anyways.

pacoW

most answers you're going to get on this board are going to be "get a reman from dis guy on ebay with a 25yr old optical sensor".

Whatever you buy get a good warranty.

vette196

Yea, dis guy can help you...optidoctor search here or ebay. Contact him direct, it's cheaper than buying through ebay...BTW his name is Brad

https://www.corvetteforum.com/forums...thumbs-up.html

https://www.corvetteforum.com/forums...thumbs-up.html

fake

Do not forget the water pump and zerex g30 anti freeze and special thermostat for the LT1 engine only

Tom400CFI

WE DON'T KNOW.


Get the one with the best warranty.

grandspt

I just installed a Petris Optispark bought from ZIP for my GrandSport. Finished the install last night and the car starts and sounds good. I am going for a ride today to see if my misfires are finally gone!
I also replaced the plug wires yet again, but this time I purchased Taylor 8mm Universal set (73251) and purchased the Opti Distributor boots (46052) separately (boots were a real pain to install but they are very secure and worked well in the end). I cut the wires and loomed them around my headers, they are no longer stuffed behind the power steering pump the way the factory did it.

ChumpVette

I’ve been running the Petri’s opti for 2 years now. Been running perfect.

Mr. Peabody

Now THAT"S good to know

Tom400CFI

Eh.

I went 5 years on a NAPA unit.

Currently at 2 years on a Sac City one.

dizwiz24

Sure, if you dont mind being broken down on the side of the road, with cars whizzing past, like having your car unavailable for a week or more as you wait on another made in china replacement, and then ruining a weekend day replacing it.

how about just get the optisparks that are reliable and dont break? Thats the OEM ones or optidoctor ones w/ mitsubishi optical sensor.

For those that will say ‘my oem one broke at 25000 miles, as mine did’ - yes the 92-94 had a design flaw that is easily corrected by adding a vent. Once added its a reliable setup

a long warranty is just a band-aid for a manufacturer to sell a product with an unreliable reputation.

except the warranty never covers the tow, inconvenience and labor costs :wink

jph46

Same here on it's 3rd year,great customer support?..

Tom400CFI

Geeezus, Aklim. Holy cow...the fear has got a grip on you, doesn't it? Yikes.

I've not seen enough evidence of the success of the opti doc...although it's looking good so far. As for the rest of your made-up reasons...I don't live my life, governed by fear, so I wouldn't know.

MatthewMiller

I think you need to do more diagnostics before you dive into this. I doubt it's your opti. Your symptoms could be a bad high-res signal from the sensor. However, this should throw a CEL with a DTC code that will tell you with certainty. Also, if I recall correctly this won't manifest from a cold start - it only happens once the engine is in closed-loop mode. If those things are not happening, then something else is probably the cause.

grandspt

Skipping at high RPM can be the Optispark. I had this happen with no codes. I replaced the Optispark and my high RPM misfires went away completely. It pulls to redline easily now. I also had an issue where when I turned on the Air Conditioner the idle would drop and the engine would almost stall.
The Optispark fixed this as well. It also cleaned up my idle in general.
My Optispark had a bad bearing and the disc was bent hitting the optical sensor.
To me it is unbelievable that an OBD2 car didn't set a code for this. But it can happen!
Exhaust all possibilities first before replacing the Optispark.
I replaced my Coil, ICM (if you have an LT4 use a Borg Warner CBE122 or else you will get an engine light), Plugs, Wires were new but I rechecked them, MAF clean the wires with electronic contact cleaner, Fuel pressure, Vacuum lines, etc.
Good luck!

MatthewMiller

That's a good point. If the problem is the Opti's bearing, then it would make sense that these things are happening and maybe not throwing a code. If it's bad enough to interfere with the actual cap and rotor operation, then it won't throw a code. Possibly ditto if the disk is hitting the sensor, as it would recover the signal for part of every rotation...I guess. Anyway, it's not that it can't be the Opti - just that the OP should really do his diagnostic homework before diving into that job, especially if it's an original OE unit on his car.

grandspt

MatthewMiller I totally agree with you and don't take me wrong about the other posts they are all good recommendations. Always exhaust all other possibilities before changing out that damn Optispark because it is not a fun job.

Tom400CFI

The two opti's I've had that failed, the both failed gradually (gave me plenty of warning) but never generated a code. He first one would break up at high RPM first, too. Still, you can prove it before replacing parts.

MatthewMiller

That's good info. How did you diagnose that when it occurred at just high RPM? Does it show up somehow on a data log? Also, when breaking up at high RPM would it do the infamous tach-bounce thing too?

Tom400CFI

The tach needle would bounce during high end misfire. It was obvious, too.

It was also heat related and as time went on, the hotter it got, the lower the RPM the miss would start. I covered it all, RIGHT HERE with pics and vid.


The second failure, it would just stop running, randomly, as if you turned the key off. A few minutes later, it would start and drive away w/no issues. NOT heat related. I could prove that one easily w/my scan tool hooked up. One day driving to work, it did the symptom. Car was in gear, engine spinning. Tack read zero. Hi Res "0". Low Res, "0". No CEL b/c the engine just doesn't "think" or "know" that it's still spinning. Details, HERE

MatthewMiller

grndspt, ^^^ here are your next diagnostic moves! Let us know what you find out.